You can get to them now.
With patience and skill you can get to any camp in the game, just put on your favourite pair of walking shoes and start walking

. Most of the camps are easy to get to, but some are camped by high level aggroing mobs and the most difficult cause large parties difficulty.
Also you are going to want to get to the other cities. Follow the road south, past Tranquil and through scene change and get to Thanalan. Follow the road again (picking up the camps and the city of Ul'dah) to the ferry dock on the coast. Take the ferry to Limsa Lominsa and pick up the city there. You could take the airship to these places but you will get a better feeling of the landscape by walking.
As for Coerthas, it is available and there is lots to do there, but the city is not yet open. Similarly the final zone (Mor Dhona) is open and there is lots to kill, but no city, and it is dangerous.
The game isn't small, you just haven't discovered most of it yet, there are no boundaries to your exploration, just monsters to avoid.