Download VEXcode V5: https://www.vexrobotics.com/vexcode-download. The Pro version is text (C++) only.
Connect your laptop to the brain and update the firmware. You'll have a better experience using a USB-C cable if needed.
Write some code, "download" to the brain and run. "Download" complies the code to be machine readable and uploads to the brain.
As standard they are fitted with a green "18:1 gear cartridge (200 RPM)", that can be replaced: https://www.vexrobotics.com/276-4840.html