Python is most commonly viewed as the Swiss army knife of scripting languages. It has millions of packages and great online support with big communities of people that are there to help you. There's also Go, made by google and commonly seen as a better alternative to Python when it comes to networking.
It all depends on the game. For me, the LUA would be a good start to write scripts especially on Garry's Mod or Roblox. Of course you need a knowledge of C/C++ to inject your script on the game
python / go / js / move and above have already told you why exactly the first two languages, but you need to learn the basics to quickly join the development
