First, I to want to thank you and your comrades for taking care of us, while we're over here fighting in our own political arena.

The answer to your question though, is pretty much up to you. What do you want out of it. Is your goal to just have fun, or to be competitive. Or maybe it's a little of both.
I too hit the big 50 last year. I still plan for this year to shoot mbo. I have never shot in the hunter class, but I think that is a good place to start. You can do both things there. Just have fun or as the scores reflect from that class in order to win be very competitive.
It's also determined upon the equipment you select to shoot. Pins or scope, short stabilizer or long one, 4 inch vanes or short vanes. You choose what you like or don't like.
I would probably start off at the local shoots in the hunter class, and see how my scores stack up with the rest of the class. Maybe the next one shoot seniors or something else. That way you have a better idea of what to expect when you go to on of the national events.
There's a classification for most everyone, you just need to find the one for you.
Most of all have FUN.