At this point in the game, you need to be realistic with yourself regarding what you are up against, because to get into a position to be on even the low end of competitiveness will take an effort that would far exceed what it would have taken to just work hard and get good grades in the first place. It will cost you cash that you probably don't have, and take time that you probably don't really want to put into the effort.
There is no shortage of fantastic students that want to go to PA school, and those are the folks that get accepted to programs. Each school gets hundreds of applicants at the very least. Many easily get over 1000. They don't have to take risks by letting one poor student in when there are 5 other applicants of that seat that are just as compelling AND have a track record of being able to handle rigorous coursework. The coursework is challenging for a decent student to stay on top of, and someone who struggles will be sunk. How does an admissions committee member justify turning away a good catch in favor of someone who can't demonstrate basic mastery of material? How are you going to prove you are able to sit through hour after hour of lecture and spit that material back out in a matter of days?
Before you undertake pursuit of PA school, ask yourself what you will do to set yourself apart from other applicants with excellent stats. At a minimum, you'll need to retake every class you got a C in. You'll likely also need to retake any classes that you got B's in as well because you will certainly have to go overboard showing that you can master material. That's really what a gpa and a transcript history show about you.
A lot of people have an outdated impression that PA school is there for folks who had some academic hiccups, but bounced back. The kind of bounce backs that make it into PA school are students that had brief setbacks, not poor students who have a paper trail of B's and C's, with a smattering of token A's. Every now and then you hear of someone turning things around after graduation and becoming a PA, but it's so much more rare than the masses of students with great numbers that get in. The minimum requirements you see out there are just the bare bones numbers... To have a chance, you need to be well above those, and you currently aren't near them. As well, many programs base their stats on undergrad grades, and won't factor gpa from post bac grades, so if you don't get those numbers up through retakes, you won't even get looked at. So in essence, you could have become a paramedic, but because your gpa won't make the cutoff, your application won't make it past the first filter. The department secretaries and staff will just take your file out of the pile before it goes to anyone who could possibly decide on your attendance. Even the most excellent healthcare experience won't be a compelling factor.
So you have a river to cross and it a a big one. Even as a nurse, I don't know any new nurses hitting the workforce that didn't at least have good grades. PA as a profession is even more focused. So think very carefully about your plan because it's going to take much, much more than shadowing and mediocre health care experience to break into PA school. I know this firsthand, and I experienced it several years ago when I was applying to PA school before I became a nurse. I had a much better gpa (>3.1), had top notch HCE, and retakes of classes I fared poorly in. I also has a post bac degree. I had interview invites at several schools but not nearly enough to guarantee a seat: I skipped out on two because I was to interested in the schools, but I wasn't a sure thing. It's only gotten worse since then.