I had shingles a few years ago. Could one get shingles a second time and should I get vacinated?

Yes and yes. You can indeed get shingles more than one time and the vaccination can help lessen the chance of recurrence.
Yes and yes. Shingles can occur more than once, the same way you can get chicken pox more than once. It is rare to get it a second time though. The shingles vaccine is approved over 50 years old, however current reccomendation from acip is that individuals receive it at 60.
Yes. You can get another flare up of shingles and it usually happens when you are under any type of stress (surgeries, etc) that decrease the immunity of the body and therefore the reactivation of the virus. The vaccination is recommeded for anyone more than 60 years old, even the ones who had the disease already.