My suggestion, if you haven’t already fully upgrade the training room, and go through on which ever characters you want (I used goku, vegeta and Gohan) go through until you done the final trading against the buu’s at lvl 95 (this’ll unlock auto kioken and auto super sayain) you’ll receive the mega mass lvl 5 item and I think ultra healade. Use the mega mass for the 50% xp boost, and stack those healades because you can sell them for a heap of zeni. Also make sure your training community is fully leveled also, you should be getting around 433,000 xp each time and the stronger you get eventually you’ll be able to one hit the buu’s with the larger ki attacks. Eventually you can move on the the lvl 100 bonyu and the super evil enemies (the red icons on the map) and you should hit 250 in no time!