So close.... I think?

commands.TankDrive.java

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

package frc.robot.commands;

import edu.wpi.first.wpilibj2.command.CommandBase;
import frc.robot.Robot;
import frc.robot.RobotMap;
import frc.robot.subsystems.DriveTrain;

/** Add your docs here. */
public class TankDrive extends CommandBase {
    public TankDrive() {
    addRequirements(Robot.driveTrain);
    }


    private void addRequirements(DriveTrain driveTrain) {
    }

    @Override
    public void initialize() {
    }

    @Override
    public void execute() {
    double leftStickY = Robot.oi.GetDriverRawAxis(RobotMap.LEFT_STICK_Y);
    double rightStickY = Robot.oi.GetDriverRawAxis(RobotMap.RIGHT_STICK_Y);

    Robot.driveTrain.setLeftMotors(leftStickY);
    Robot.driveTrain.setRightMotors(rightStickY);
    }

    @Override
    public boolean isFinished() {
    return false;
    }

  
}

Main.java

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

package frc.robot;

import edu.wpi.first.wpilibj.RobotBase;

/**
 * Do NOT add any static variables to this class, or any initialization at all. Unless you know what
 * you are doing, do not modify this file except to change the parameter class to the startRobot
 * call.
 */
public final class Main {
  private Main() {}

  /**
   * Main initialization function. Do not perform any initialization here.
   *
   * <p>If you change your main robot class, change the parameter type.
   */
  public static void main(String... args) {
    RobotBase.startRobot(Robot::new);
  }
}

OI.java

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

package frc.robot;

import edu.wpi.first.wpilibj.Joystick;

/** Add your docs here. */
public class OI {

    private Joystick driverController = new Joystick(RobotMap.DRIVER_CONTROLLER);

    public double GetDriverRawAxis(int axis){
        return driverController.getRawAxis(axis);
    }}
    

Robot.java

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

package frc.robot;

import edu.wpi.first.wpilibj.TimedRobot;
import edu.wpi.first.wpilibj.command.Scheduler;
import edu.wpi.first.wpilibj2.command.CommandScheduler;
import frc.robot.subsystems.DriveTrain;


/**
 * The VM is configured to automatically run this class, and to call the functions corresponding to
 * each mode, as described in the TimedRobot documentation. If you change the name of this class or
 * the package after creating this project, you must also update the build.gradle file in the
 * project.
 */
public class Robot extends TimedRobot {
  public static DriveTrain driveTrain = new DriveTrain();
  public static OI oi; 
  




  /**
   * This function is run when the robot is first started up and should be used for any
   * initialization code.
   */
  @Override
  public void robotInit() {
    // Instantiate our RobotContainer.  This will perform all our button bindings, and put our
    // autonomous chooser on the dashboard.
    oi = new OI();
  }

  /**
   * This function is called every robot packet, no matter the mode. Use this for items like
   * diagnostics that you want ran during disabled, autonomous, teleoperated and test.
   *
   * <p>This runs after the mode specific periodic functions, but before LiveWindow and
   * SmartDashboard integrated updating.
   */
  @Override
  public void robotPeriodic() {
    // Runs the Scheduler.  This is responsible for polling buttons, adding newly-scheduled
    // commands, running already-scheduled commands, removing finished or interrupted commands,
    // and running subsystem periodic() methods.  This must be called from the robot's periodic
    // block in order for anything in the Command-based framework to work.
    CommandScheduler.getInstance().run();
  }

  /** This function is called once each time the robot enters Disabled mode. */
  @Override
  public void disabledInit() {}

  @Override
  public void disabledPeriodic() {}

  /** This autonomous runs the autonomous command selected by your {@link RobotContainer} class. */
  @Override
  public void autonomousInit() {
   
    // schedule the autonomous command (example)
    }
  

  /** This function is called periodically during autonomous. */
  @Override
  public void autonomousPeriodic() {}

  @Override
  public void teleopInit() {
    // This makes sure that the autonomous stops running when
    // teleop starts running. If you want the autonomous to
    // continue until interrupted by another command, remove
    // this line or comment it out.
   
  }

  /** This function is called periodically during operator control. */
  @Override
  public void teleopPeriodic() {
    Scheduler.getInstance().run();
  }

  @Override
  public void testInit() {
    // Cancels all running commands at the start of test mode.
    CommandScheduler.getInstance().cancelAll();
  }

  /** This function is called periodically during test mode. */
  @Override
  public void testPeriodic() {}

public static void tankDrive(double rawAxis) {
}
}

RobotMap.java

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

package frc.robot;


public class RobotMap {

	public static final int Left_Motor_1 = 0;
	public static final int Left_Motor_2 = 1;
	public static final int Right_Motor_1 = 2;
	public static final int Right_Motor_2 = 3;
	
	public static final int DRIVER_CONTROLLER = 0;
	public static final int LEFT_STICK_Y = 1;
	public static final int RIGHT_STICK_Y = 5;}

subsystem.DriveTrain.java

// Copyright (c) FIRST and other WPILib contributors.
// Open Source Software; you can modify and/or share it under the terms of
// the WPILib BSD license file in the root directory of this project.

package frc.robot.subsystems;

import com.ctre.phoenix.motorcontrol.ControlMode;
import com.ctre.phoenix.motorcontrol.can.TalonSRX;

import edu.wpi.first.wpilibj.Joystick;
import edu.wpi.first.wpilibj2.command.SubsystemBase;
import frc.robot.Robot;
import frc.robot.RobotMap;
import frc.robot.commands.TankDrive;

public class DriveTrain extends SubsystemBase {
  private static final int LEFT_STICK_Y = 1;
  private static final int RIGHT_STICK_Y = 5;
  private TalonSRX motorLeft1 = new TalonSRX(RobotMap.Left_Motor_1);
  private TalonSRX motorLeft2 = new TalonSRX(RobotMap.Left_Motor_2);
  private TalonSRX motorRight1 = new TalonSRX(RobotMap.Right_Motor_1);
  private TalonSRX motorRight2 = new TalonSRX(RobotMap.Right_Motor_2);

  public void initDefaultCommand() {
    setDefaultCommand(new TankDrive());
  } 

  public void setLeftMotors(double speed) {
    motorLeft1.set(ControlMode.PercentOutput, -speed);
    motorLeft2.set(ControlMode.PercentOutput, -speed);
  }

  public void setRightMotors(double speed) {
    motorRight1.set(ControlMode.PercentOutput, speed);
    motorRight2.set(ControlMode.PercentOutput, speed);
  }
  public void driveWithJoysticks(Joystick controller, double speed) {
    Robot.tankDrive(controller.getRawAxis(LEFT_STICK_Y));
    Robot.tankDrive(controller.getRawAxis(RIGHT_STICK_Y));
   }
}