A homebody is sent by an old man to a parallel world. Technology is advanced there, but entertainment is lagging behind, so...
Become handsome? That's the first requirement. Improve his memory? Definitely. A photographic memory would be great. Then give him mastery of musical instruments and top-tier musical talent.
You think all I can do is sing? I can write screenplays, too. As for acting, forget it, it's too tiring. I'll just start a company and hire other people to act.
In short, this is a homebody's journey to the top.
This novel and its characters are entirely fictional. Any resemblance to actual persons or events is purely coincidental. Do not imitate.