I’m in basically the same boat as you, gpa started on the low side but I’ve got it up and I’m hoping that will help me as well. I also really want to go to upenn. In order to balance out my less than stellar grades I’m trying to get a really good SAT score (over 2100). Starting a club is great but I would recommend a LOT of sat prep. you need to get that as high as you possibly can. Lack of honors and ap classes is a problem at my school as well. A high sat score is important because it will show wharton how you measure up against applicants from more rigorous programs. Have you considered applying ed? There is a higher acceptance rate applying that way.