Managers is it okay to call and ask if you are hiring or have any job openings?

Hello I'm 17 years old and have no work experience. I was volunteering at an R'club working with kids cleaning after them and organizing their play areas. I become a senior next school year and it is very important that I get a job this summer so that I can save for college and I'm having a very hard time trying to find a job. I'm a very cheerful person, energetic, full of enthusiasm and a very dependable person. I have been an honor roll student since elementary school I have a GPA of 3.5. I live in south st.petersburg and was hoping if you have any jobs that are available. I have looked just about everywhere and just about everybody is not hiring, I do not meet qualifications or my age is a problem. I've filled out application online and called to to see if my application has been reviewed and I don't get in touch with no one. I'm willing to work anywhere that will allow a 17 year old to work in the st.petersburg area. Could someone help me out