gamespro

Best answer as chosen by Asker / Ratings
You're going the right way, the buggy is supposed to break down and afterwards you are supposed to go to cosmo canyon. While you're there which is part of the story the buggy will be repaired.

The first enemy skill materia you can obtain is after you beat the boss in Hojo's lab, the enemy skill materia was inside the glass case holding Hojo's experiment but there are other places to obtain it.
The first place to get it which I mentioned already is inside the Shinra building.
The second is in Junon in one of the houses along the path leading to the ship you used to get to Costa Del Sol you will find a basement with the enemy skill materia.
The third is in the City of the Ancients in the house shaped like a shell.
The fourth is in Chocobo Sage's house which is located on the northern continent surrounded by mountains but it will be a long time before you can go there.