Hello Tom! ^^ Thank you for submitting your homework today. Kindly take note of the corrections that I made. Thank you! ^^

Tom: I have a good fitness because when I was in military, I received many trainings.
Correct: I have a healthy body because when I was in the military, I had a lot of fitness training.

Tom: I am good at treating my computer because I have learned about it.
Correct: I know how to take care of my computer.

Tom: I don't eat what only I want and I can eat everything.
Correct: I am not choosy in food. I can eat everything.

I'll be a chemical engineer because my major is chemical engineering. -Correct

Tom: I am not afraid about adventure, and I always enjoy encountering new things.
Correct: I am not afraid in taking an adventure. I always enjoy encountering new things.