Which race should I check? (White and Native African)

You do not have to be a descendant of slaves to be African American. More recent immigrants from sub-Saharan descent are African American. I think the key here is “sub-Saharan”. Algeria doesn’t “count” that way.

That said, if you feel biracial, I’d say you have a claim to that. I agree with @lookingforward . It will come out in the wash if you are honest.