The beat should almost always stay at 0 db. Don't touch the beat because you will lose bit depth. Its not ggoing to snap and sound how the producer intended.
Record low and mix the vocals lower. You want a nice, small balanced waveform because you will add compression and other things that will bring it up in level.
If You think it sounds good, try lower 3 more db and check. You want to bring the vocal down as much as possible to leave headroom for the beat. Beat will sound better and probably have more bass. Don't let the vocals overpower the beat.
If you just started mixing, there are good chances you are mixing too loud.