im getting tired of trying to level up and not being able to because of people that are a far higher level than me does the firing range give weapon xp?
No. The only way to level up is by playing multiplayer, or completing the single player campaign. Single player missions will only give you xp the first time you complete them though. If you don't like playing with people of a higher level than you, maybe add a level difference cap to your lobbies. Shoccer and marksman are two gamemodes where level difference doesn't matter as much, as long as you can aim well.