I am playing TP for the first time ever. I know what everyone is thinking 'What took you so long?'. Anyways. Where is the Twilight World located after you complete the Forest Temple?
Go to Hyrule Field, to the northwest portion where the wall of twilight is. There, you should be able to enter the Twilight Realm.
Is that where the bolder is blocking my way or where the gate is?
Is that where the bolder is blocking my way or where the gate is?
It is neither. The boulder blocking your way leads to Castle Town(but you can't clear them yet).
Which version do you have by the way? Since the two versions are mirrored from each other, the Twilight Realm's opening should be either east(in the Gamecube version) or west(in the Wii version).
Go North of Coro's House to get into Hyrule Field. When in Hyrule Field, go Northwest if on Wii, or Northeast if on Gamecube.