It's good to see you have an idea of how triggers work, and with practice you will surely create nice maps.
However, this one in particular does need some improvements. I'll highlight a few areas, so that you can work on them :)
1: Map detail. This map was fairly plain, both players buildings seemed randomly placed, and resources also seemed randomly placed.
For some inspiration, open up a random map game and check out the terrain.
2: The storyline. I don't think it had one, except maybe 2 enemies at war (could have meant to be like a game VS computer, but a storyline in custom scenario is always nice).
3: Triggers. For some reason, it displayed "You Win" for the get-go. I had a look, and you had 'Not' ticked in the conditions, so it doesn't use them conditions. It also had all units and buildings destroyed as a win condition, which may be a bit much. Consider using "is dead" on Agamemnon. A trigger to lose would be nice, to make it challenging. For example, if Arkantos dies.
4: Try not to rush it. We're all here for a long time (I hope so anyway..), so just take your time doing each scenario.