Rebirth of Dragon Ball I just want to live Forever

Gus died suddenly for no apparent reason just after he stepped out of school!
With the help of the system, he was reborn as a baby. The system did not tell him any information except that he could practice immortality with the help of the books in the system, and the system was annihilated!
Adopted by Dr. Breeve and named Ponzi, he became Bulma’s second brother.
what to do? Should he save the earth or just focus on his own dream of immortality?