Building levels in the main world is a bit harder to do if you leave "Noob" island too soon. Stay at the "Noob Island" and build up until you reach level 10. By the time you reach level 10 in "Noob Island", you should have enough items gathered that the Jellies, Little Jellies, Little Chorpy, Jelly Nut, Royal Jelly and all the other creatures drop.

Go to Seyon in Adventure Plains to get the Price Checklist quest. Then, go to Ulysses in Zant for quite a bit of experience. He will ask you to give his price checklist to Seyon. You can keep going back and forth between the two for easy experience.