How often should i feed my new baby leopard geckos? dusting?

Hmm I've read so much that its begining to get confusing! their both around 3-5 inchs. I have 1/8 crickets and mini mealies(theyll get wax worms when there older for treats). How many crickets should i feed each of them? Some say 3-5 while others say till their full but in that case they say to watch for over wieght. And how many mini mealies? Should i offer both food items? and how often sould i dust them? Do i dust the mealies too? what calcuim is the best? I have 3 different kinds. Ive read that D3 is bad for leos is that true? any help!?