well as i got suggestions from others i learned that doing more than one bicep exerice a week is useless. now i do more back exercises and switch off between different bicep exercises every week. but i was wondering if i could do reverse grip curls once every week including my other bicep exercise( standing curl with curling bar, preacher curl, or dumbell curls). would the reverse curling and my bicep curl be over training? if so should i just stick to wrist curls?

I laugh because this was the sort of question that I'd ask when I started weight training.
Don't worry about it. Being new to weight training, I doubt you'll over train. You just need to make sure your workouts are well balanced. Which is seems that you're working on.
If it makes you happy to throw in an extra set of direct bicep work, and doesn't interfere with the rest of your workout, go for it!
So many cries of inequality stem from one of group
of people doing little or nothing and then bitching
about another group that actually does something
to improve their lives.
DISCLAIMER: