How can I do well in all my subjects I am just 13

I don't want to be harsh here, but you need to learn to read the instructions and follow them. Your question was originally posted as a reply to someone else's post in the Taxes forum. The purpose of having these forums is so you can post your question in an area that is what your question is about. Plus posting it as a reply to somsone else's question breaks up the thread.

So my advice to you is to try and read and understand what your assignments are.

Do all your home work.
Study hard for your tests.
Ask lots of questions.
Never be afraid to ask questions, even if someone gives you a hard time for asking them.
My algebra teacher used to say, "Always Ask Why!" That turned out to be good advice.
Stay up with your homework; try not to get behind.
Don't get discouraged when you are having trouble. Get back on the horse and keep trying.
Once in a while, you are going to get a teacher that you don't click with or who is burned out. If you can, get out of his or her class as soon as possible. Take another class if you can. If you have to stay in the class of a burned out teacher, try to find a way to connect with that teacher and learn from them anyway. Make friends and learn what you can. You can learn something from anybody.

Good luck!
Asking