Please check my sentences gramatically (1.4)

I don't have sufficient time to exercise. I want to finish excercising within 2:40 ( specify, is this mintues, and seconds, or hours and minutes? etc). I have two ( you can only use a number sign when the number is 10 or greater) best friends. One's name is David, the other is Erica. I met David when I was in middle school. I thought he was a stuck-up person because he didn't talk about himself. At that time, I tried to make a good relationship with people. David made offense of people including myself. However; as it turned out, we had a lot in common like playing basketball and swimming. Similar hobbies made us friendly towards each other. I misunderstood him. He was just a reserved person. Erica is my role model. She is energetic, and confident in everything. I try to be like her, moreover she is meticulous she always checks whether I have forgotten my belongings. Sometimes she lectures me because I'm kind of a person who is clumsy. I've learned many things from her. It is too hard to say who is better because I love them exactly the same. They are my best friends forever.