10 gallon ADF tank questions?

ok so ive chosen to put 4 african dwarf frogs in my new 10 gallon tank by themselves. i got a small decoration and four plants for them. I will be getting them some time next week. i wanted to know if i can put all four in at once, and i herd u should feed them a variety so i will be feeding them frozen blood worms and something else, so what else should i feed them? and i will be using the long tweezers method but i cant find them anywhere! so if u know please tell me a place that sells long tweezers?(walmart, target, petsmart, petco, Walgreen's?) and if you could tell me how much to feed them(exact amount) please tell me. if you know anything please help me