Is it worth renewing a green card?

Have had a green card since i was a kid (which is now expired) because my mother applied for them but circumstances changed and we never ended up moving. To be perfectly honest i dont know a whole lot about them so just out of curiosity i thought i'd ask a few questions on here.

Couple of questions. Firstly, hypothetically were i to renew it, am i even allowed do that seeing as i had my shot and didnt take it? Secondly does having a green card specifically mean i have to be moving permanently to the states? The reason i ask that one is because i hope to live in America for a short period some time soon and i was just thinking whether it would make sense to get a short term visa or see if the green card can help me at all. Obviously if the answer is the green card is only for people who wish to reside in America permanently then i wont renew it because i like where i live and dont want to risk any hassle from immigration.

Sorry for the long winded question, just curious. Any info appreciated.