Answer:
An MLB Superstar.
Explanation and translation:
Because in one part of the text it says the following:
My dad prefers to play baseball in the backyard of our house. With his glove and his bat, he thinks he is one of the superstars of some major league team.
Greetings.
A mi mejor amigo le gusta luchar en la escuela.
Answer:
All the SER verbs are correctly, congrats!