I got my current one on eBay, but it's really too small. It's a little bit tight. I need to get a larger one, but I don't have a local store that sells them.
You can sometimes find helmets at Walmart, believe it or not, but it's probably best to go to a motorcycle shop so you can check the fit. That way, you won't get another one that's too small.
My dad goes to the Harley shop and buys all his motorcycle items there. It's expensive but he wants the best. I did not know Wal-Mart sold bike helmets.
My dad bought his at the local Harley shop but seeing as you don't have one you can buy one from Harley Davidson online. They give you a sizing chart so you can measure your head to get the right size.