Lua/GLua

https://wiki.facepunch.com/gmod
Recommended^
At the side you can see all of the resources you will ever need
Just fuck around dude. That's how you learn to code. Make something literally random.

If you are more of a visual learner and cannot read for some reason(Although literally most of coding is you know.... reading....)
https://www.youtube.com/channel/UCFpuE-Q...X-VJ_l7pbw
Although this guy is a druggie and OD'd, still has some good tutorials