Is the jump in difficulty supposed to be this steep? The AI in Standard difficulty is stupidly lame, they get stuck at age 2 most of the time, barely construct and build armies, and it attacks too little, it truly is boring as hell. Yet on Moderate diff. the AI practically rolls stomps and is impossible to keep up.
What I would recommend is to have something in the middle between Standard and Moderate, because as it is the jump in difficulty is just too much, it does not make any sense.
Just pick a civ and learn a build order.
Usually against the AI all u have to do is rush them
You can experiment with the handicap slider. Try Standard and 50% handicap.
With any decent build order you Can win 1vs1 on Hard (the AI cannot stand rushes) Just learn one or two civs, get the main mechanics and play
Youtube has now lots of content for DE só just check tutorials
Try playing with a treaty against the moderate AI. This way you get to play really cool late game battles, I have never played AoE III but this is the way I play AoE II.