Unable to play multiplayer.

Okay so I just installed halo 5 and played the campaign but I tried to play multiplayer afterwards. I can’t play at all it said that I don’t have the proper servers for my fireteam. I’m playing solo and don’t want a fireteam. It’s very frustrating. Iv been trying for two days now. Nothing. I can’t find a solution at all. Someone help. Xbox support won’t help. 343 won’t respond to anything