Is there any chance you can talk to the teacher and see if they'd be willing to let you join their AP Bio class? You can't really do labs in an online setting and labs are important in science classes! Missing out on the labs is a big deal.
I'd say stay in your other AP classes. Don't drop to do online AP Bio.
I am not sure if it is normal, but I think that most professors would be very happy to talk to an interested student! In my experience, professors love to talk about their work/research! You could try emailing her. Make sure you keep your email short and sweet - professors don't have a lot of time to read long emails.
If your high school doesn't offer calculus, college won't hold that against you.
If you want to go into medicine, what I find more concerning is your earth science --> chem --> bio --> AP bio track. At some point you NEED to take physics in high school, especially if 1.) you are considering top schools 2.) you want to go into science or medicine. Chem, bio, and physics are the science trifecta that college look for and that will prepare you best for undergraduate science classes.
Assuming we are talking about happy memorable events in no particular order I have two:
1.) My husband proposing to me and my parents surprising me at an event very special to me the next day to celebrate.
2.) Graduation day when our Dean included something that I had written in his speech (my undergrad had approximately 30,000 undergrads). So that was very cool!
Agree with above. If you want to stay in the health field (nursing, med school, etc) it will help. If you end up wanting to go to grad school for biomedical research (i.e. Masters or Ph.D. in molecular biology, genetics, biochem etc) it will be a nice experience to add to your CV but not a requirement like research usually is.