If not already installed, you need to install samba server. The example below is for Debian (and derivatives)
sudo apt install samba
Ensure samba isn't running before continuing.
sudo systemctl stop samba
Make a backup of the configuration file
sudo mv /etc/samba/smb.conf /etc/samba/smb.conf_backup
Now recreate the config file without all the comments
sudo bash -c 'grep -v -E "^#|^;" /etc/samba/smb.conf_backup | grep . > /etc/samba/smb.conf'
Set passwords for the users (replace 'grumpychunks' in the example below with each username in turn)
sudo smbpasswd -a grumpychunks
Now by editing /etc/samba/smb.conf, add the required shares, for example
[homes]
comment = Home Directories
browseable = yes
read only = no
create mask = 0700
directory mask = 0700
valid users = %S
guest ok = no
[storage]
comment = Storage Volume
path = /mnt/storage
browseable = yes
read only = no
create mask = 0660
directory mask = 0771
valid users = grumpychunks
writeable = yes
guest ok = no
Before testing from a remote system, don't forget to start samba again
sudo systemctl start samba