Randomly at startup when put car in reverse it seems like there is no power breaks, will go away and stop normally for rest of trip. Any advice, my 16 year old drives this car.

 

Your car has a vacuum pump for the power brake system. There is very little manifold vacuum when first started and that pump is there to solve that. Commonly the plastic vacuum switch that controls the pump breaks, which causes the pump to run until it seizes up, and sometimes blows the fuse. The top of pump is visible under the hood in the lf corner of the car, switch is near that also.

Temporarily until you get it fixed - if you rev the engine up and let it return to idle - that will create manifold vacuum (as the engine is slowing down the pistons are trying to pull air past the closed throttle plate) and help the power brakes work better after first starting.

 

you should also hear the vacuum pump kick on when you do a cold start.