This is a pretty broad question but maybe I can try and break it down for our other verified members who can better assist you.
Is there any way for me to increase my grades and get my GPA higher even if I do get A's?
Straight A's are straight A's. There is no other way of increasing your GPA other than that. Now, depending on the credits each class is worth (i.e. 5 credits vs 2 credits), you could see your science vs cumulative GPA increase at a fast rate at the beginning of your first year of school (depending on how many credits you take per semester). If this is not what you are asking, please clarify.
How can I bulk up the rest of my application?
Again, this is a pretty broad statement and I'll defer to those who've recently checked each box in terms of being a competitive applicant for med school. Plenty of WAMC threads exist to help solidify what is required and what is considered competitive for medical programs. As a start, what exactly are you doing NOW in terms of being competitive? Are you volunteering? Are you holding class office(s)? Are you shadowing?
I would strongly recommend finding a mentor this early on as well to help guide you in the right direction. Anyway, hopefully this helps cater answers or promote further questions for our other verified experts.