Some basic things with aeon that should help you:
Poke your opponents out with 2K/B/A, they should not come close. This is the range where aeon struggles without meter. If they try some longer range moves or to poke back with AA/BB backstep 3B works wonders. It's one of his main sources of damage.
If you have enough meter to do at least one CE aeon becomes a monster! Many people think he struggles under pressure, this is not true if you know how to counter it. Many opponents try some frametraps on him because aeon is very slow but they are easily predicted (siegfried or maxi during their stances come to mind). GI their attacks!
If your opponent doesn't have meter to re-GI or guesses wrong they'll eat your 1B BE which is a one-hit-kill if you spaced right. Try these few things and your aeon should improve relatively fast. It's nothing more than a few basics but they are very important. Don't be aggressiv, he has not the tools to rushdown. If you want to keep pressure on your opponent 33A/Throw-Mixup is usually enough.