Congratulations on your acceptances! Penn and Rice are both great universities, but I will discuss Penn because I am most familiar with it as my D is a current bio major there.
You will work hard at Penn. The introductory bio classes are weed out classes with harsh curves. My D spends 6-8+hrs on homework per night and more during exam weeks. But, Penn is a supportive and collaborative environment so your peers will be working just as hard. Research opportunities are available to undergrads via the Center for Undergraduate Research and Fellowships (CURF). Many of D’s friends got lab positions through CURF during their first semester.
Although Penn may have a smaller Latino population, they try to provide cultural and social support to their Latino students. The Center for Hispanic Excellence: La Casa Latina exists to serve the needs of Latinx students. If you choose Penn, look into it. My non-Latina D attended some of their events and had a really fun time. https://www.vpul.upenn.edu/lacasa/
Lastly, Philadelphia is a major East Coast city. It’s diverse, vibrant, and there is always something to do. Penn or Rice—there is no bad choice. Best of luck to you.