GO GO GO!
Note that I stated that it can be safe. Understand; people will be running through obstacles with highly pressurized tanks of non-flammable gas trying to pelt you with paint filled gelatin capsules traveling around 290 feet per second. This is not inherently safe. It takes responsible play to make the sport safe and enjoyable for everyone.
First safety topic is the mask. It must completely cover eyes and ears, yet afford excellent visibility and adequate hearing. Single lenses are more affordable, but tend to fog more often. Dual lenses will still fog up on heavy perspires; believe me.
Breathing in through the nose and out through the mouth can help defog goggles on the field. Under no circumstances should the mask be removed on the playing field, on the walk to the playing field, or on the return from the playing field. Many parks will have multiple games running on different fields. Find out where the designated no-fire area is and help everyone adhere to the rules.
When you get ready to buy equipment, spend your money on your mask first. You will enjoy renting guns much more than you will enjoy renting masks. You aren’t likely to smell the last person who used your rental gun.
The style of play really doesn’t affect mask choice that much unless you really, really have to color coordinate your playing ensemble. If this is the case, I would advise you to try some other form of recreation. The best mask for you is just the best mask for you. Your friend with the narrow face is going to get a different fit, feel, and field of vision from his mask than you; if you have chubby cheeks. Try on several masks if there is a store that will let you. If not read extensively and ask other players. None of them will lie about their mask if you ask specific questions as you complement their playing ability.
Like: Does it pinch?
Does it fog more when its hot/cold outside?
Is it easy to replace lenses?
Do the lenses scratch easily?
Is there a problem with glare at any particular time of day?
Can you hear well in the mask?
Is it easy to adjust for size?
Does it stay adjusted for size?
Does it hold smells?
Is it easy to clean after being hit?
How much do replacement lenses cost?
Are replacement lenses readily available, (I.e. are the sold at the fields you play)?
Get answers to these questions that satisfy you, and you will probably never need to buy another mask if you maintain it properly. You will, however, need to replace lenses at the first sign of chipping, splitting, or crazing of any kind.