I have two routers which is 2.4 and 5. I just bought this phone just today and I just realized it wasn't set to 5 GHz. Now I have no idea how to solve this problem. Help.
Welcome to Android Central! Go to Settings>Wi-fi>Advanced and see if there's an option there to choose between 2.4 GHz, 5 GHz, or Auto. If you don't see that, then the phone should automatically be able to see both bands. You have to make sure your router is properly broadcasting on 2.4 GHz and 5 GHz, and make sure the SSIDs for both are different.
If it still doesn't see your router, make sure your router's 5GHz radio is on channel 64 (the phone works on that one - it may work on others, but that one is certain).