In terms of extracurriculars, as well as keeping good connections with professors, you are certainly on the right track.
Gradewise, that's a whole 'nother aspect to tackle. Broadly, I would focus on your work efficiency, study habits, and balance in courseload. For more specifics among those three, you have to personally diagnose what could be the difference in that descrepency between the GPA you desire and the GPA you currently have. I would also read Cal Newports "How to be a straight A student" for some instant tools and tips you can apply for your coursework.
3.25 is not the worst start. Just learn from your mistakes, most importantly, as a mistake is only a failure if you didn't learn from it.
I am not an admissions officer, but I have talked to some, know many many students who have gotten in every year, and have seen many trends.
I think most people admitted fall into these three categories, in my opinion:
1. Recruited because of high achievement in Athletics; Come from Famous/Super Rich Family - with very possible Donation to School;
2. They were Extremely talented in one area of EC other than recruitable sports (Music/Arts, STEM, etc.). (I'm talking about National, at minimum, + International Achievement. Basically a super "shining" point that distinguishes them from other applicants.)
OR a very shining point in their background (extreme circumstances yet still achieving great academic records)
3. For those who are not category 1) and 2): All the parts of their application story clearly aligned and pointed to wholesome, genuine passion/interest. The schools believe that based on the students' complete story and application, they will contribute to the school's mission and and be a good fit. This is a very generalized way to put it, because every applicant has their unique "story", but this is the least-convoluted description I can think of. Example:
I think this is the biggest reason why everybody says its "not just your Standarized test scores". Are you president of 5 completely unrelated clubs you started just to put on your resume, have you done an internship/camp just because it looks impressive on your CV? Or did you do that entrepreneurship camp or internship at your friends' dad's company because you are genuinely interested in business, scientific research/competition because you really like science, or volunteered at X for the hundreds of hours you claimed because you really care about it?
There are also many other background factors - perhaps not as extreme as those in category 2, (Legacy, First Gen, URM, Well known High School), that can boost your application too.
NOTE: You also have to keep in mind there are only so many spots in these schools. There is NO DOUBT very exceptional and qualified kids who perhaps have equally worked their butts off in high school, or maybe DO fall into category 3, get overlooked and denied admission every year. When you have tens of thousands of smart, talented kids applying and you can only accept 5-14% of them, there obviously are some excruciating tough decisions.
@Cue7 I don't get exactly what you mean by Penn not having varied "types" of students. I see where you are coming from in that Students tend to get very involved with many on campus groups, such as clubs, societies, and sports, but I do not know if this purports into a "lack of diversity", especially compared with other schools with high achieving students who also juggle a lot of things in their life. There is this feeling at Penn that your peers are doing and achieving so much and you need to stay on pace, but again I don't think this is too different from many other top tier schools.
First off, they were already admitted to their specific undergraduate school because their intended pursuits align with the specific goals of the school and careers they are going for. Aside from the combined-double degree programs (yet another example of Penn caterizing to specialized future pursuits), The students in Nursing (only undergrad program in the entire ivy league) were admitted because they showed in their application that they were very focused and passionate about pursuing nursing. Same with Wharton and business/leadership. Again, you can say that about other top tier schools too.
Moreover, I know many students who do a lot of activities, but it is focused and aligned with their professional goals. Penn is very pre-professional and for example, you will see a good chunk of Wharton students who do LOTS of activites, but they are all business-related (investment, consulting, finance, management etc. club, wharton-[insert country] society/exchange, Case competitions). You may find the same with Pre-med students (Pre-health frat, some medical club, volunteering work, working in a lab).
Three main things IMO:
> Dining Hall Food Sucks; You are forced to have meal plan freshman year which you will see is very costly vs. the quality of food (Some other on campus non-dining hall places - where you use "dining dollars"- like houston market or frontera have great food though, i'm just talking about the ones where you use a "meal swipe")
> Pressure due to competitive/very preprofessional atmosphere
> School Spirit for sports is not great
Bonus: I hear the CAPS (psychological counseling service) isn't the greatest. Haven't been there myself but everybody makes jabs about it.
Definitely manageable. 4 credits isn't too hard if assuming you won't party every night. Writing seminar is an easy A if you don't screw around; Spanish is fun and not too hard (im assuming 110 or 120?). Have not taken nor on the Political Science route however so I cannot say too much about it. Finally, hardest class there definitely Econ 001. It's not super super hard but its not a walk in the park. PM me if you want advice for 001.
I understand your concerns for the "intimidation", but I wouldn't worry. Most of the rumor is probably because like 50%+ of the kids you'll meet in CAS will say they want/are thinking about doing Econ as a major or minor. So the Intro to Econ classes are weedout classes. Stuff gets harder with sophomore year+ Econ classes (you actually will have to use calculus) but at that point if you are fully committed to getting an Econ major you should be able to stick with it.