First you are going to need to contact a local skydiving center wear you can take the AFF (Accelerated Free Fall) course so you can skydive by your self. AFF consists of class time and 7 jumps you do with instructors wear they show you how to move and get oriented with skydiving on your own. Once you do those 7 AFF jumps you can then jump by yourself and then you need to get your Class-A license.
You need to get at least 25 jumps to get your class A license, then after that you need to get your B, C, then D license. You only need a C license to be an instructor but you need a D license to be a tandem instructor. You have to get at least 200 jumps to get your C license among other requirements, here's a link-http://www.studentorg.umd.edu/cpsc/LicenseReq.html
As far as cost, it's expensive and it varies a little depending on where you live. AFF will cost over $1,000 and after that to jump you will have to rent equipment ($50 a day roughly) and about $22 to get a lift up in a plane. And if you want your own equipment it costs thousands of dollars. I hope that answered your question. Just call a local skydiving center and ask how much their AFF course costs.
If you have any more questions feel free to let me know!
