Some baseline suggestions.
First. Attend a game and use a rental for your first outting. It gives you a good idea of the premis of the game and allows you too meet a few people in your local area. Also face to face time with other players will allow you to obtain a multitude of opinions as well as ask stupid questions without fear of being burned to an ember.
If you do purchase a gun, I suggest getting verified and doing a private sale from a reputable person or hitting an in stock CANADIAN retailer. But start small and accumulate gear over time, alot of people rush in and plunk a few G's on the table befor they are ready. Its not worth it.
Also remember this is a game, having fun is priority number one, expect to meet people and enjoy the social aspect.
Above all, as mentioned previously get out to a local game and ask questions.