That sounds good @vacohp If I may just offer my opinion here, it sounds to me that at this early, early point in your journey, you should follow the advice the other posters have presented re: college and major. I’d skip on pharmacy school unless you want to be a pharmacist. If we fast forward and you make it into med school, you should really keep your options open (most incoming med students don’t know the nitty-gritty details each specialty entails. It’s much better to get exposure to everything during med school - and especially rotations - and decide at that time).
Having said that, it’s good that you’ve envisioned your purpose in medicine and specifically pediatrics. If you do end up in peds, keep your options open and make sure that ped cardiology is the right niche you want. There are several ways you can subspecialize in peds, in fact just about as many as if you went internal medicine. Find out about which niche resonates with you during peds residency and go for that.
I hope you understand that the super-majority of patients you’ll have in ped cardiology will have congenital conditions, and that will create a different work experience vs working with neonatology cases or as a peds hospitalist. I think you’d find it better to let your specialty choice grow more organically from your experiences vs declaring it in high school.