"Je vais faire mes devoirs demain."
Here's a breakdown of the sentence:
* Je: I
* vais: going to (present tense of the verb "aller")
* faire: to do
* mes devoirs: my homework
* demain: tomorrow
You can also use the future tense if you want to emphasize that it's a definite plan:
"Je ferai mes devoirs demain."
Here, "ferai" is the future tense of "faire". Both translations are correct and sound natural.