You can read our documentation
https://plutonium.pw/docs/server/t6/setting-up-a-server/

If the server is just for yourself you can skip the server key part and replace the port in the bat file to let's say 5000 and connect to it using /connect localhost:5000 in your game's console
You gotta start the server while the game is running if hosting on the machine you play on (unless you do some tweaks maybe)

For bots use this
https://github.com/ineedbots/t6_bot_warfare

Add seta bots_manage_fill "12" to auto add bots each game to get started, as such, in your dedicated.cfg file