So I was driving on the freeway and suddenly my brake and battery light
turns on and then my steering wheel wouldn't turn. Can someone help me what could be wrong?

I've already checked all the fluids (brake, battery, steering)
and they are all full.

 

altenator probably

 

by any chance could a missing drive belt cause the malfunction of my steering wheel and the lights to come on?

 

When you say it won't turn, do you mean no matter how hard you try to turn the steering wheel, it won't move or turning the steering wheel is extremely tough and I have to put a lot of effort into making it turn?

 

its tough to turn the wheel but it turns.

 

something to do with the power steering.

 

I actually checked my car again and one of the belts is gone. Would that actually make the battery and brake lights turn on and cause the steering wheel not turn easily?

 

belt turns the altenator and the power steering pump...

 

If you're missing the belt cycling on the left hand side when facing the the engine bay, then you are missing the alternator, power steering belt. Just replace and you're good to go.

 

As others mentioned, yes, that is your problem. Just remember, with the alternator belt missing, you were/are running just on battery. If you ran the car at all after the belt came off, good idea to give the battery a charge.

 

+1 on the battery charge.