I coach a recreation/competitive team for elementary school-aged girls, so perhaps I could offer some advice.
In addition to contacting local schools to ask about coaching, also contact the gymnastics centers in your area. If they don't already have cheerleading classes or teams that need instructors or coaches, perhaps they would be interested in someone volunteering to get a cheerleading program started. That is how the team I coach got started: the girls in our gymnastics classes knew that we (their teachers) were cheerleaders and asked if one of us could teach a cheerleading class. After three years, it's just grown into a competitive team.
Also, contact a major cheerleading organization (UCA or NCA, for example) about coaching seminars. I know for sure that UCA runs coaches clinics where you can become a certified coach, and most of the other major organizations do the same. If a clinic is not available in your area, at least contact your local Red Cross (or other similar organization) and sign up for classes in first aid and CPR - these are certifications that any school or gymnastics center is going to ask that their coaches have so that they are covered in case of emergency. Certifications in first aid and CPR could help you get a coaching job.
Good luck in your quest - I'm sure any team would be lucky to have you as a coach!