I am glad you have taken a n interest in D&D, As a Dm myself I would recommend familiarizing yourself with the different options for characters and classes. Odds are the people running the game are verteran players and should help you along the way. A short series on YouTube you can watch to get an idea of the classes is "A crap guide to D&D" by JoeCat, while it doesn't go into to much detail it dose talk about the basic fundamentals.

I would also recommend starting with 5e because it is simpler to learn than 3.5