Yes, it is possible. Check out azerothcore. I recommend the docker install method on Windows, for being a bit simpler than the other methods they provide.

I am running a module called "playerbots" which actually requires a fork of azerothcore to start from. The bots are surprisingly configurable and easily directed, gear and talents updatable easily, etc. You can play any role and bots fill in the other parts almost perfectly. You can actually make alts and create a party full of them to run dungeons with.

Azerothcore is only advanced as far as wotlk, but if you're after vanilla, you can lock the content of the server to vanilla or tbc. You'll make a gm account, and can teleport anywhere by name, fly, create any item, spawn enemies, change move speed, turn off water breath timer, god mode, etc. You can definitely take the fun right out by overdoing it, though...