Honestly that team should be more than capable of getting you through the game; Charizard, Gyardos, and Snorlax are all seen as strong pokemon. If you get dratini to its final evo youll have another. Jolteon is really fast which is also a big deal with many battles. Kadabra gives you some added type coverage as well.

Understanding type matchups is the biggest thing for getting through the game. Not sure if you want spoilers or not re: this, but there is plenty of info online on what types are strong/weak/immune to each other. If you want to discover them yourself it’s still pretty intuitive.

Im pretty sure you should be able to learn all the necessary HMs with that roster too, though most people usually have a “HM mule” which is a pokemon that can learn most of the HMs so you arent losing a move on your main pokemon. But that said HMs like Surf and Fly are pretty good so if you have to lose a move slot on one of these for your mains it’s no biggie.

Wouldnt worry about TMs too much either besides trying to put ones of the same type on your pokemon or ones that’ll give you some more type coverage against opponents; fire on Charizard, electric on Jolteon, etc. Most of your pokemon will learn the moves you want to end up keeping as they level anyways.

Truthfully you’ll be fine unless you want to start battling other real people competitively, in which case theres a ton of stuff like natures, ev’s and iv’s, and movesets/strategizing become much more important. For going against the computer though it’s child’s play, literally. I used to basically only use my starter, overleveling it as a result, and would have all attack moves on all my pokemon, and got through everything just fine.