In case you don't get it, this is after seifer takes the president hostage.

EDIT: i mean How do i get to dollet academy? or whatever it is called?

Ah, you mean Galbadia Garden. You're meant to take the train to Dollet, although Dollet isn't actually where you have to go. Instead, the train will automatically leave you at a station along the line called 'East Academy'. From here on foot you're then meant to head up to the the forest between the two mountains, which will trigger a scene with Laguna. After that part ends you then appear on the other side of the forest and should be able to see Galbadia Garden on the world map in the distance, which is your destination.

This is the general direction which I can remember (goddess it was so long ago I last played FFVIII), so hopefully this hasn't been too confusing (if so, I'm really sorry). :)

After the train leaves you in East Academy station and you cross the forest (where the Laguna's dream sequence takes place), Galbadia Garden is just up ahead.
You can't miss it