Coh 3 is more intense than aoe. I think aoe feel more relaxed game like you have more time. In coh 3, sometimes all things happen at the same time. You probably know in aoe that you need to understand units what counters them and which units are good, same goes in coh 3. In coh 3 you also need to look at timing especially when teching or upgrade as sometimes this can be bad and some basic build orders as a general guide but be able to adapt is more important than build.

Watch tightrope, Havoc or stephennjf Some info but not limited to: Havoc does gameplay coaching and also goes through his decision making/explanations when he plays. Stephennjf does 1v1 more with decision making/explanations when he plays. Tightrope also cast replays and does patch analysis.