Where can I practice creating levels for 3rd person games?

Question

Game development

Hello, tell me please.
Where can I create levels / locations with mobs and then play the same level myself? Maybe in some editor or there are some patches for games? What is needed is the practice of creating levels of games for the 3rd person. For example, such as Gears of War, The Last of us or Batman.
Thanks for your help and your time.

Answer 1

Project Spark or Creation Kit for Skyrim .

Answer 2

redkit.cdprojektred.com - editor for the second witcher, good docks, third party

Answer 3

Serious sam first