Shrimps are really cool little creatures to have in a tank but i would advise taking time to look into the species you want before getting them just to make sure they are easy enough to take care of and don't need any specialised treatment. I had some shrimp once (can't remember which species) and they were amazing things but seemed to die without warning. If your tank is only small with little current in the water avoid shrimps that feed with fans as these tend to need a lot of water with plenty of flow to cycle food out of.