Did you get live mealworms? If so they can be offered in a smooth plastic feeder or tin can (be sure there are no sharp edges for birdie feet) They will crawl out of wood or cardboard or anything they can get a grip on.
They can go out whenever the temp is warm enough not to freeze them. Dont let them get wet from rain they'll drown. If its too soon you can keep them in the fridge, they'll nap in that cool of an environment. If you keep them at room temp they'll turn to larvae then beetles and make more. If you need to or want to raise them No water, apples or potato
(raw) and plain bran flakes for food. I keep mine in shreded newspaper.
I mix freeze dried mealworms (available through..ME!...) in with my mixed seed
which has a high nut content. Between that and my suet i have 2 Carolinas that visit quite often.