I just got an email from Paris Casino saying I was selected to participate in their blackjack tournament with one free entry. I'm interested in doing it but not sure how this all works. It also says, "Re-buys will be available for $100 on a first-come, first-served basis and based on availability." Not sure what that means. Is there a strategy for playing in aBJ tournament? If so how do I learn?
Yes, there is separate strategies for playing tournaments, because you are not so much playing against the house as playing against other players. Playing strategies can get really weird and seemingly non-optimal (from an EV point of view).
Ken Smith who used to operate the first blackjack site I participated on, "blackjackinfo.com", now runs Blackjacktournaments.com which as you might guess is devoted entirely to blackjack tournament info and play. He also has published at least two books on blackjack tournament play, 'How to win more blackjack tournaments' and a second volume, the ever so cleverly named 'How to win EVEN more blackjack tournaments'.
I, myself am not really into blackjack tournaments, having participated in a just a handful, because for a professional player there is risk involved. But for a non-professional player, there is good value EV, with no variance other than time, in participating in tournaments, especially tournaments where your entry is comped.