1. Red Tide dont have multiplayer. Red Tide is only a singleplayer stand-alone-addon.
2. there are some Clans - but you dont need a clan-member to play MoW online. when you play multiplayer periodic, you will find friends verry fast.
3. hmmm. hard to answer. 1st you should play with players who are also "new" in MoW. but best is playing in team with players who have experience - how to learn useing/handling different units.
i think western community/players are very helpful. you can also ask players with experience makeing a "testgame" & give you tips playing online.
how complex is the game? hmmm. look for "ingame" movies at YouTube. you will find enough videos & show you how MoW is working.