2 answers
Luis "Lou"’s Answer
A good foundation in math and science is essential to succeed as a mechanical engineer. And aptitude and desire to understand and work with mechanical "things" is also key.
Wael’s Answer
I agree with Mr. Herrera. Math and physics are the spine of mechanical engineering. What would help also is fixing stuff! With supervision off course, take apart your toys that are not working, try to figure out what is wrong, fix it, then put them back together. You might not be able to revive it but you would understand its mechanical structure.