[@Lugia]

How about electricity? That way if you go up against any flying or water types you have a move for them. Ice is also a good one if you need to deal with ground, dragons, and for some reason grass types though you cover that with fire anyways. Straight up dragon element is a bit cliche for charmander lines but it's decent too, so long as you're not up against any faeries. Ice is pretty much the only other thing dragon would be weak against and I don't imagine a Charmander will have any issue with ice pokemon. 

[@SleepingSilence]

Do what you gotta do matey. Don't be afraid to ask your own questions considering that IC your dude really doesn't know, so it would behoove him to find out. unless you're the type of guy who lets other people do the learning for em, as I said you do you.