HCA: Hermit Crab Association

New-ish Owner here! My 8year old came home with two small hermit crabs. I remember having them back in the early 2000s in college but now there’s so much more information available. Lots of good info out there to help them thrive. Trying to get their tank set up ASAP and having to make-do until we get a terrarium and better set-up.
Any top tips for getting them healthy quickly?
Also, what I’m finding the most challenging is finding the right tank with the right top. It’s like it doesn’t exist? How to keep humidity in! I’ll research here!
Anyway, Sandy and Seaweed say hello. Glad to have this space to help figure out how to get them healthy and happy.

Welcome!

For a lid.. you can use the screened lids that are prevalent, just wrap them in saran wrap... Or you can get plexiglass cut to the right size at a local hardware store (or big box like Home Depot or Lowes) for not terribly expensive.

If you haven't already looked at the care sheet, start with the 'basics' one and then go from there for everything you need to know.
As for a lid, I used plastic wrap on the top of the first two tanks I had. I now have plexi glass that has been cut to fit, with a corner out for ventilation.