Chaos or Remnants? I love those guys but they aren't exactly new player friendly.
KUTT (the clan I am in) plays mostly in siege mode. We coordinate well and use strategy.
NH is another clan that tries to coordinate and use strategy. They are very very noob friendly. Most of their members are noobs, but they try.
Astralis, TKoV, and SoW are all good clans with solid players and solid leaders. TKoV is mostly a battle oriented clan. Astralis and SoW probably play equal parts in both siege and battle.
KUTT probably plays more in Siege but we have a diverse membership base and we spend plenty of time in duel, battle, and siege. We are also very active in strategus which is similar to single player campaign but it's clans fighting.
Remnants and Chaos are very good, but tend to be more about personal skill rather than strategy. I know that Chaos especially is very active in strategus and excellent in strategus tactics. Either one of those are good clans, although last I heard applications to Remnants were closed.
The King of Boats is correct here.
All these clans have good players and leadership. As you play just notice who's on and see who you like the best.
As has been suggested, duel server with a decent/good player is the best way to improve. Especially if you're in TS/mumble/etc with them to have them tell you what you did wrong or to explain things to you. There's a lot to learn about the game and you might learn things even if you have played other games that are similar. Every game has its own quirks and play style.
