Anyone who starts new in a hobby will be lost in the abbreviation or lingo. Dont worry. You're not the first one. I still dont understand half the things people talk about here LOL
As for your age, unless you're so old you're going to drop down and die, you're not too old. Sure, you're not as athletic or active as us younger folk, but imo, you'll find that wits and patience is much more useful than speed and agility.
As others have said, READ LOTS! Being that we live here in Canada, there are specific laws and etiquette regarding firearms and airsoft guns/gear that you may want to familiarize yourself with.
Welcome to Airsoft Canada and enjoy your stay =)