Hi MEENag,
Congratulations on your new mattress … I think you made a great choice 
A mattress protector is a good idea to protect the mattress from the normal body fluids and oils that we lose each night and from the buildup of dust mites and the possibility of accidents as well. It’s a lot easier to keep your mattress hygienic over the years by washing a mattress protector than cleaning the mattress. There are some mattress protectors that have very little effect on the feel of a mattress.
You can read more about the different types of protectors in post #89 here.
Phoenix