Ooh now you've gotten me very excited! I'll offer a few tips
For a trio, I'd recommend a cage in the range of 20-40 gallons. Nothing much bigger than that for just a trio (mice don't fair well when kept in huge cages unless there's a larger group as well as good amounts of stimulation)
For a wheel, literally anything will suffice, other than a barred wheel. I don't personally recommend mesh wheels just because they tend to be noisy and lower quality, but mice, due to their running patterns being different that that of a gerbil or hamster, can handle a mesh wheel just fine. I personally use the wodent wheel jr for my little ones. Saucers are great fun too! Just go for something around 8 inches if at all possible
Make sure they have lots of toys. Bird ladders make great toys for them! Unlike hamsters, they do not need the rungs filled in. Mice are made for climbing and perching high up so filling the tank all the way to the roof is the way to go
For food, I'm still doing a lot of research into what is best, biologically, for mice. However, the community generally agrees upon vitakraft or a similar type of parakeet seed mix. A small amount of veggies daily is great too.
Any bedding will work, but avoid super dusty ones. They only need 3ish inches, but you can give as much as you'd like
Clean once a week, or every other week. Mice do tend to stink though! You can completely change or rearrange decor, mice truly don't mind, and become incredibly bored by cages that never change
And something I wish I had known before I plunged into mice- they're nothing at all like hamsters! Things that would make a hamster owner shudder upon seeing in a ham's cage, are perfectly okay for mice! For example, weekly cage cleanings, the fact that fleece is perfectly okay-even fleece strips as nesting material, open bird ladders, mesh wheels, items with chains, and smaller cage sizes being ideal. Mice are pretty low maintenance, but totally fun! I can link you my favorite mouse forum if you're interested in learning more
Good luck, and make sure to share pics!