I only managed to get past lvl 1 gold star and that was with help -_-
So does anyone have good ideas on how I should play this generally?

Get a feel for the lvls, continue practicing, and you'll find out.
In some lvls gold star is easy, in some nearly impossible.

Go, and find your path.

Also, replay, replay, and learn from previous tries....

Often it is just taking advantage of the "stupid" AI.

For instance, their attack order is not well thought out. If you can delay, they will crash into your defense allowing you to counter attack with better odds.
Also, they seem to prefer attacking neutrals. So sometimes you can delay to let them take a neutral. Then, you can easily take their land with only 2 men.

Some of them take more analysis of the board and settings that others. Once you see the trick, it is a lot easier.

There is a bunch of yt levels for the earlier levels as well. That being said, i recommend doing the levels and playing some multiplayer before hunting for the gold.