IMHO, finding a premed school is slightly different from just finding a good-fit school without considering premed factors.
All the advices above are really good. With the med school admissions move to competency based admissions, more weight are going to be put on activities outside classroom. If the student is “on the bubble” academically, less time for that student can be put on activities outside classroom. Not to mention the possible anxiety which might come with that uncertainty.
Personally I think “just build confidence as a freshman by taking it easy” is a huge mistake. Students should take a mix of difficult and not-so-difficult courses to test the water. Sooner or later those “difficult” courses are going to come. It is better to know if it is feasible to achieve the above-the-threshold GPA as soon as possible. “On the bubble” is the worst scenario. Adding a more difficult major like computer science/etc.as a backup probably makes things worse. If the student can’t even handle the premed courses without other hard/time-consuming courses, what are the chances that the students would be able to handle both? Plus different majors have totally different internships.
There is no one-size-fit-all answer to OP’s question. OP is smart enough to think about this. I agree with @Creekland 's statement 100% “When kids from my school are hoping to go to med school and ask for my advice it’s simple. Look for an affordable school you like where you’re in the Top 25% of entering stats”. It is not good to play tennis in a league full of people like Novak Djokovic if one can’t play tennis at that level.
OP should view the course material as its competitor, not its classmates. Yes, at this level, the material is much more advanced. We have reviewed and written some solutions for Orgo exams recently. It is definitely not easy. A high level of understanding of the material is required to answer the questions correctly. (We actually get 2.5 points since we found out TA graded one question wrong — this is the joke … we gained 2.5 points but we weren’t even there. 
) OP should strive to learn the material at a high level in a school at this level. Otherwise, OP should look for other schools with lower standards.