If you are trying to boot a headless setup of Raspbian and don't have access to the router the following may be what you are looking for.
- Download the latest Raspbian Lite
- Use an OS image flasher like Etcher to flash your Raspbian dmg file onto a microSD card.
- Once the microSD card has been flashed you will want to do some configuration
- From the terminal
$ cd /Volumns/boot
- Create an ssh file
$ touch ssh
- From the terminal
- Create a file for preloading your network settings
$ touch wpa_supplicant.conf