Huge difference! I like both at different times, for different reasons.
The plus side of online play is there's nothing you really have to do other than make your decisions. The blinds, dealing, even your chip stack is managed for you. You can sit on the couch in your underpants and no one would be the wiser haha.
Downside though is that all of your decisions have to be made, solely on your cards, the cards on the table, and how the other players have been playing. You can't pick up any personal
tells from people other than maybe their betting patterns.
Live games you manage your own blinds and chip stack, you may or may not deal depending on the game. It's sometimes fun to actually interact with the other players outside of a typed chat bar. You get the chance to pick up on any tells whether it be tics, voice variations, certain movements, nervousness, faked confidence, whatever. I find it's more fun basing decisions on something the other players have said, or done, instead of just the cards and
odds.
I've never really played extremely high stakes or anything. I figure if I don't have the money I can afford to lose I shouldn't be
gambling with it, but I have played a few casino tournaments with buy-ins under $500, as well as their low stakes table games and done pretty well for myself.
I think if you get the chance, you should give it a try. It's definitely something to experience.
If it's something your nervous about, why not just get a group of friends together for an evening? It doesn't have to be an expensive, or overly competitive thing. I play monthly with a small group of 6-7 friends who just enjoy playing as a hobby. We only play $5 tournament style games where 2nd place gets their buy-in back and 1st place takes the rest. It keeps it friendly, no one can lose more than say $20-$30 (depending on how many games you play), but there's still the opportunity to make a bit of money. Just an idea... you'd get to see what live poker is like, learn to handle the chips, all the while just having fun with some friends.
You'll have to let us know what you think of the online vs live games, if/when you do try playing live.