First and foremost should be a mask . You need to make sure you feel comfortable , safe and able to play a full game without hitch . Best thing to do is once you find a local place is to ask fellow ballets if you can have a look or if you can make your way to a shop and try some on that way as well .
It's a bit difficult in my opinion for advice because it all boils down to personal preference, but normally you'd get people telling you that pro flexes, grillz, events and I4's are the way to go.
It's the same for markers as well, ask to try them get a feel see what you like and dislike.
What's your style of play?? Speedball/sup air? Woodsball? Scenario??