In addition to what Preston said, it would be difficult to get your own profile approved if you don't have any freelancing skills to offer. Also, if you're not a graphic designer yourself, then how will you know what to say in proposals on your friend's behalf? How will you scope a project to come up with an accurate price and timeline? And how will you answer any questions that a potential client might have?
It sounds to me like your friend should open his own Upwork account, because if you're not a designer yourself, then frankly, I don't think that you'll be able to help much.
