If you don’t find an AI difficulty level that suits you properly, you could experiment with the Handicap optional setting.
It increases things such as villager efficiency, unit HP (maybe just vils), bonus damage dealt, decreased bonus damage taken, building HP, unit train times, and a few more I’ve probably forgotten by the percentage you give it.
So if you change your handicap level to 110%, everything effected by the handicap setting will be 10% better.
That could help with creating a fair matchup.
If you wanted to improve as well though, I recommend the Art of War tutorial that comes with the game.