Question Hero Shooter tools?

Hey all,
I'm looking to make a multiplayer first person hero shooter (similar to Overwatch or Paladins). I can code singleplayer by myself but when it comes to multiplayer I'm clueless. I'm trying to find a template, tool, framework, or some sort of starter project to help me make it. I've looked on the Unity store and can't find seem to find anything that has what I need. Here are the basic requirements:

- Character or class selection (I can modify the classes)
- Abilities of some sort
- Domination game mode or something similar
- Guns and melee (obviously)

Any help or recommendations would be greatly appreciated