The greatest thing you can do at any age is to begin by speaking with the older generation. They tend to know the most about your family's history. This is where you'll get the greatest information. Most people are at a disadvantage because they start too late in life, and have missed out on speaking with those whove already passed on. So, you're in a good position.
Another thing that I cannot stress more about starting your research is too learn efficient research and documentation methods. Too often now do new reseachers rely heavily on what is not only posted here, but on public trees. But not all of the information you see here or on those public trees are correct, and it can take you down the wrong road and waste a lot of your time. Learn how to properly source information, and it's important to save copies of documents and record where you find your information.
Start keeping those records, and set up a system for organization. Don't rely soley on computer programs. It's good to have it organized in physical files as well as digital ones. Don't forget to update in both your physical and digital files.
Going back to speaking with older family members. Don't just focus on grandparents and great-gandparents. Talk to aunts, uncles, great aunt and uncles, cousins, distant cousins, and I've even spoken to people who weren't related but were knowledgeable of my family. Keep notes on these interviews, and even record those sessions with a digial recorder and or video camera. You won't be sorry, and you wouldn't believe how much you'll learn.
You don't neccesarily have to join a genealogical society by the way, and I don't think its absolutely neccessary or practical at the beginning. It also costs money, and those memberships pile up. You can look for websites online and groups devoted to your family. And keep an hear out for reunions. Those are great for connecting. Keep those contacts in a safe place by the way. Record the names and contact information for people you correspond with.
And remember to come back to the boards often, and keep posting. I've been contacted on post I made in the late nineties which proved succesful. There may be a clue tomorrow which wasn't there today. And be sure to search terms that may be relateable to what you're looking for. This helps to narrow it down. If you just start reading every post on your surnames board you'll go crazy, so if you're looking for info on your great grandmother and she had an unusual name like Lovelace. Do a search on the McCane board for Lovelace.
Oh, and don't be too discouraged over your age. I started when I was 8 years old.