My son is 17. he worked at Target for a few months over the holidays, I tried to import his W2 as mine and change it to his, and that did not work. How do I add that?

You do not add your son's W-2 to your tax return, even if you are claiming him as a dependent.  He will have to file his own tax return with his W-2, if he is either required to file or chooses to do so (even if he is not required).