It is one of my small number of autographs. I got it as a kid, in person at a restaurant. I know it is authentic. I am thinking for preservation purposes sending it in to psa/dna.
I'd just put it in an archival plastic sleeve, but then again I don't have stuff authenticated.
That one is really up to you.. SInce it is personalized, and you got it in person, I doubt you plan on selling it. Unless you want it slabbed, I'd just throw it in archival plastic sleeve as JBK says^.