Re: Family History?
I too have a 'family history'. It's not something you should worry about at this stage in your life. Just be a bit more diligent about checking in with your doc every year. Don't put it off. Yes the odds might be a bit more likely to get a cancer, but those regular check-ups are the best way to keep up on your well-being. I've a hypo thyroid where you have a hyper-one. I've not read of any conections between cancer and thryoid so far- so, that's an area you don't have to worry about.
Just keep that 'family history' written down somewhere [I use a page in my phone book, where I keep addresses and all kinds of other useful stuff] so you can recall it years from now should you need it for any reason.
In the meantime, enjoy beeing a teenager! I wish I were one rite now!