The biggest key to success in this game is activity. Sadly, you can’t just get by that. Any amount of skill wont mean shit if you’re not on.
Once everyday for a 1 speed world (1 hour per day)
2 times a day for a 1.5 speed world (1-2 hours)
or better than 3 times a day for speed 2. (2-3 hours)
These a rough estimates, you may be able to get by with less but not if you want to remain competitive. Also those times are averages, on days where you are under attack or are launching attacks you will obviously be on a lot longer and other days you may not have more than 10 mins simply to check to make sure nothing is incoming.
Note: Also, despite how ever many sitters you have that can watch it "whenever you go out" don't trust them to be able to play it well. As your account and theirs grows you will have harder and harder times with finding sitters. Base this off your time and not the time of your friends. Despite what many think about how good players having sitters round the clock, it’s often just not true, oftentimes it becomes a lot of sleep deprived nights and 02:00 alarms.
So choose with speed world will work best with your life and what units/settings you enjoy and select that world and stick with it, don’t play a lot of worlds. Just because X world is the newest or just started it doesn't mean it’s the right world for you. Quite likely the world that has been going for 6 months would be better, just because you cant start at the beginning or core of a world doesn't mean you cant be successful and gain a solid rank(if that’s what you are going for). In fact, many times it’s actually easier to build a large and successful account on the rim, later in the world rather than in the beginning.
Also get involved in the politics and the P & P of the world to get your name out, but refrain from becoming a spammer. ONLY, post well thought out pieces; you're better to say nothing than to spam or say something stupid. There are a lot of good players who are never known because they never speak out, that’s not in itself a bad thing, but name recognition can open a lot of doors that would be otherwise closed, such as new tribes, friends, and allies. Further, it will help you stay better connected to the global political atmosphere which can be a big help when it comes to later in the world and your looking for a new region to colonize into.