I just got my turtle from pet smart 2 days ago. No clue how old he is. He really isn't eating that much he is stay in his shell and hiding hole most of the time. Is there something wrong?
Give him time to get adjusted to his new home. Be sure you are not using any type of coil bulbs. A russian for petsmart is usually wild caught and any where from 5 years to most likely around 8 years, but no way of really telling for sure, just guesses. Be sure to look in the russian section and read all the sickies for their care. Anything Petsmart told you could be and usually is wrong.
Read the care sheet. Post a picture & tell us about your habitat. Pet stores typically sell the wrong equipment. Some of it is downright dangerous. If you follow their advice there are problems you'll need to fix.
If your set up is truly good - not according to their advice - then hiding is normal and part of adjusting to change. If it's not right and needs adjustment, then hiding is a sign of its unsuitability and need for change.