Dialog needs a certain type of formatting:

"It's a ball. You need to catch it!"

I shrunk down as the coach bellowed at me again. So yeah, I can't catch a ball, big deal.

"Okay practice's over. All of you can go home…except for you Sara." The coach yelled at the team and everyone ran to the waiting cars.

Now I am a usual 16 year-old, but the coach is a monster, super tall. If he has a nice side I haven't seen it.

"Sara, if you want to stay on this team you have to learn to play better. Every girl can catch a simple softball, but you. You can hit and throw, but if you can't catch then you can't play on the field. Try practicing at home. Maybe you can shape up before the first game."

Separate narrative from speech. Paragraphs improve reader comprehension. But you've got the quotation marks OK, and it's easy to make out who's speaking.