My current team is only a lv35 Charmeleon. I have already beaten the first..

Yes well not technicly raise more just catch more until you get to meet and battle the birds

Yes Because you can't just have one pokemon. You need a team with a variety of Pokemon.

Yea.if your only Pokemon gets defeated your skrewed lol when it comes to the elite 4 trust me youll need the whole team. Im pretty sure there are other Pokemon you probably like and want

Here's a tip: If you find that using just 1 Pokemon is too challenging, you can catch Pokemon with different types. If they are all different dual types, you will end up with 12 different types out of 17. If you want to take my tip, here are some types that will be unbeatable together if you raise them properly: Fire, Water, Grass, Dragon, Fighting, and Psychic. The most important type is Psychic. They're pretty complex. My team was: Charizard, (Fire/Flying type) Poliwrath, (Water/Fighting type) Victreebel,(Grass/Poison type) Dragonite, (Dragon/Flying type) Hitmonlee, (Fighting type) and Hypno. (Psychic type) You can use these Pokemon but maybe you can use other Pokemon of the same type(s). Sorry for taking up too much space for my answer. So the more Pokemon you battle with, the easier battling is.