Open Setup>IO>Output tab and delete any path you don't want(and you may want/need to rename some). You may also find you have more than 1 path feeding the same physical outputs so do some "housecleaning". Its probably going to take you a few time thru this to really master it, so be patient and give yourself time to learn it. Once you do, things will get better(especially if you find that customizing this stuff can make life easier
).
Any session with issues like this may need to be addressed in the same way(this happens a lot if you bring in sessions from another Pro Tools setup)