I know you didn't ask for it, and I hate giving it, but I want to just share a couple opinions with you.
1: You shouldn't buy a used helmet to protect your head. A helmet can appear to be fine, but be abused to the point it won't offer the same level of protection in an accident.
2: I highly recommend getting a full face lid. I know, you live in Florida and it's hot, and your bike isn't a 1000cc bucking monster, but it doesn't take much to do permanent damage to your brain.