To become admin on your server, you would have to access the console in game via: L1+R1+Square+Triangle, which will bring up the option to Request Admin
Once done all you need to use is the admin password, which can be found on your clanforge page. Clanforge>Settings>Admin Password
Once you have this you would just need to put this into the Console opened on game, you don't need EnableCheats like the PC version.
Also not if it doesn't work the first time please change the password that is automatically generated on Clanforge, Save & Apply then attempt once more.
Currently, there aren't any mods available at this time for PS4.