My team will be:
Should I catch my team members as soon as they are available to me, or should I wait for some of them?
I don't see why you wouldn't catch them right away. If you wait, you'll just have to grind longer for them to reach the same level as the rest of your team. Especially Dragonite. Dragonite is a royal pain to level up. Plus, more Pokémon on your team = more Pokémon to fight with.