Congratulations on your upcoming graduation and the excellent GPA trend. I won't be able to help much with the formal post-bac program selection, as I did a DIY postbac, which means I took the med school prerequisites a la carte at my local state university. However, as a nontraditional career-changing applicant, now second year medical student, I can speak to certain aspects of your post. Perhaps others more familiar with formal post bac programs can weigh in as well.
Regarding clinical experience - You have a good, strong reason for considering medicine as a career. I, however, am of the personal opinion (and I say it about five times a week on this subforum) that nobody should commit any money to their nontraditional premed process UNTIL they have gained substantial physician shadowing and/or clinical experience (paid or volunteer) (saying it loudly for those in the back, not yelling at you).
There were about 5 other nontrad med school hopefuls where I did my postbac. Two switched to other allied health professions after they shadowed/worked in hospitals and saw what doctors actually do all day long (which is to say an appalling amount of charting and paperwork). It turns out these students desired careers with extensive direct and bedside patient care activities, and nursing/PT were much better fits in this respect. But coming to this realization put them into several thousand dollars of additional debt and cost them year of their professional lives.
IMO, someone really cannot know whether they want to be a doctor until they've spent a lot of time in a clinical setting. I know this doesn't help you out much, since you're limited in what you can do due to your COVID risk status, but please please please shadow a primary care physician for at least 40 hours/5 work days before you enroll in anything.
Regarding extracurriculars - high school stuff doesn't count, unless it continued into college (i.e., your music performance) OR was a truly remarkable, unusual achievement (international awards/honors, Olympics, etc.) Med schools will want to see more recent service, and a lot of it. I'd say 200 hours is pretty much the de facto minimum to apply to medical school, and some service oriented medical schools want to see 1000+ hours!
Regarding research - This is a lower priority for nontrads. Many do just fine without any research experience beyond their lab classes. Keep doing your music research if you like it, but it's unnecessary. Be aware that, fair or not, some medical schools really mean "scientific research" when they talk about "research experience." I discussed my extensive social science research background on my application, and not one single medical school cared at all about it. They only wanted to talk about my basic science/bench research projects. One interviewer literally cut me off as I was starting to explain my social science research and said "No, we mean the project you did in Dr. X's lab, tell us about how you got involved in that."
GPA - You will be expected to maintain as high of a GPA as possible in a postbac (formal, DIY, or otherwise). Aim for a 3.8 or above. You're on a great trajectory as it stands, so keep it up.