how many people do they usually offer during april - may. im worried that they won't have enough offers. i can get mid- high 80s no problem, i just messed up a bit of my first sem.
also, will they look at my first sem, and reject/judge me?

I can't really answer that much but, I'm kind of in the same position. I'm worried I won't get accepted into it because I only got an 84% first semester, but what I did was I also applied to Environmental & Earth Sciences and got in to that. This way I can transfer into Life Science, or any other science program if I choose the prerequisites carefully for 2nd year level II programs.

Just do your best in second semester, especially at midterms and if you think you will have an overall average of mid-high 80s, they won't reject you because of your first semester I believe since a high 80 should get you in.