Daniel,

Nobody can do the homework for you but yourself. There is just no shortcut to learn 8051 stuffs. You have to spend more time yourself. Instead of asking someone to do for you, you can find tons of example programs on this site or others. Then study them and try to understand them. One day you will say "I got it!", and you will be able to write great programs and make a living out of it.

Happy Learning,
Oliver