Upper Division Nursing Application

I've really been stressing lately about applying to Upper Division nursing. I'm taking a 4 year program at a university, and I apply this semester. I'm really worried I won't make it, and that I'll be spending countless semesters trying to get in. I just have a few questions for anyone who can help:

How important is volunteering? My application does not ask for hours or contact information regarding where we have volunteered. I have volunteered at a couple places in the past, such as helping work with the disabled and at community centers serving immigrants. However, I feel like the amount of volunteering I have done will not compare to some of the sorority girls who probably had to do countless hours of volunteering (No, I am not in a sorority). Since the application does not ask for hours or contact info, does this need to be a worry?

My application also asks for any medical experience. I have very little, since I'm going to college to be trained and get medical experience . The only thing I have really done even close to medically related is take care of my parents after they got out of surgery (shoulder surgery and heart surgery). Is there anything else I SHOULD be doing or know? Is this just to see who has had a previous job in a medical field? Will this be an issue? Would doing something such as getting CPR certified help me here?

My GPA is pretty good, about a 3.4 (and I still have this semester to bring it up more), and I have to include a 500 word essay on why I think I have the right qualities to be a nurse and why I want to be one (which will be 100% honest and VERY well written).

Someone please help me, Im stressing so much over this. And thank you!