The first thing that you need to understand is; having a hermit crab as a bet is very complex. They need a lot of attention and help with their homes. That is because they are not crabs as we would usually think. Most crabs have an integral shell that grows with them. However, Hermit crabs are soft-shelled animals that need to find and replace their shells as they grow. Therefore, you need to have a way to give them shells that they would choose themselves. That alone can be a challenge because if they do not like the one you get for them, they will die.
Furthermore, hermit crabs need to have a pretty specific temperature, lower than 75F will kill them, and sitting in the sun will kill them, too. They also need a pretty humid environment of 70% or more humidity, and they are very social creatures. That means that you will need more than one, or they will become lonely, you preferably need to have 3 or more. As for their actual habitat, they need to have a pretty specific substrate, such as coconut fiber or very clean sand, and super clean dechlorinated water. The takeaway from this article is that hermit crabs are not great pets for beginners. However, if you do a lot of research, and have a lot of time to spend with them, they can make wonderful pets.