town 5 i mean Erliquin and the first quest i mean the old man under sorpigal that you have to bring something to Erliquin
You can walk back from Erliquin. Just leave the city through the front gates and travel through the outside world. If you stick to the main roads, you shouldn't have too much trouble with monsters. To get back to Sorpigal, turn north from Erliquin, and then turn east. This will take you into another area. Stay on the road there, which goes east and then turns south. After you've traveled south a little ways you'll find yourself back at Sorpigal.
Don't explore too much until you've found your way back. Once you've saved at Sorpigal, you can explore the outside world a little more, without having as much fear of dying. Traveling between Sorpigal and Erliquin actually isn't that hard... it's pretty much the first thing I did after finishing up in Sorpigal.
Don't worry about Erliquin being "Town 5", this does not mean it's the hardest town. It's actually a good place to go after Sorpigal.