I want to make sure I set up the cage correctly before I put them in, to make sure the pet store transition is as easy as possible.
I have a glass 10 gallon, I have plastic coconut huts, a plastic plant, small driftwood pieces, and large cork round. My water bowls are probably going to be the small fluker's corner bowls (are those big enough?), food bowl haven't decided yet, maybe a shell?
I got moss from Michael's "Hiawatha Evergreens Bagged" which claims no chemicals or preservatives. Is it safe? If not what to use?
I also will be purchasing extra shells with them.
How do I prepare each of these individual items?
And I know you boil shells, does that mean bringing them to a boil or placing them in boiling water? For how long?
Also for their fresh and salt water, must they be prepared before time or can they be prepared just an hour before going into the tank?
Going to use Aqueon water conditioner, and Instant Ocean for salt. Should I buy 2 gallon purified waters at my local CVS to start off and pop some salt in one of them, then use those containers to continue my stock? How accurate to a gallon must measurements be for conditioner and salt?
Also, how do I make it so they can get in and out of water bowls? These will probably be medium sized crabs, I will grab the smallest and most active I can find at the time when buying.
As for heating, I have an old heater I can use. I put that onto the back wall or a side wall of the tank? I also live in Maryland and it's getting chilly. I believe I should use aluminum and cardboard to insulate the heater. The conditions at the pet store are about 82 degrees already (it's an aquarium), so I don't need to ease them into a high temp, I just hope I can reach that on first go!
For humidity, I don't know how the current conditions are. They are in a wire cage.

Any tips would be awesome.
I also have eco earth and play sand from home depot. I will probably grab some sort of container tomorrow to mix the eco earth in.
I will have a wire top and I will cover (most) of it with cardboard and saran wrap.
I got a 100% cotton climbing net for them from Hugs for Hermies (do I need to wash it?). Also got a food sampler from her too. Will also purchase Zoo Med fruit salad food.
Thank you all so much, I just want what's best for my future pets. I really want them to survive and thrive.