Hi there, since you are interested with getting started using Unreal Tournament for creating content and levels, I would suggest these pages:
https://wiki.unrealengine/Getting_Started_With_Unreal_Tournament
https://wiki.unrealengine/Category:Unreal_Tournament
https://wiki.unrealengine/Category:Unreal_Tournament_Tutorials
https://wiki.unrealengine/Creating_a_Weapon_(Unreal_Tournament)
And also, check out the general tutorial sections of the wiki:
https://wiki.unrealengine/Category:Tutorials
https://wiki.unrealengine/Category:Community_Videos
https://wiki.unrealengine/Category:Epic_Video_Playlists