You didn't mention what tablet you have, but something tells me that it's a cheap Chinese off-brand knock-off. I advise people to avoid those tablets at all costs. There is virtually no after-sale support, little to no warranty, and no hope of a software update. Plus: in order to cut costs, cheap tablet manufacturers will not install Google Services in order to avoid licensing fees. Without Google Services, you have no Play Store, Gmail or any other Google apps. You might be able to do an Internet search for Google Play Services and Play Store apk's, download and install them... it's a long shot, but you can try.