Actual certification program doesn't really matter ...
You might consider looking for a community sailing center, local yacht club or university sailing club near you. They are a great way to get into sailing at little or no cost to you.
I'm with tap in that you might start with an end in mind. Once you learn to sail, when and where will you get the opportunity to sail. Certification opens doors when you go to charter a boat in the future but it doesn't get you on the water so you can gain experience. You need access to a boat for that.
I started with the local university sailing club. They provided me sailing lessons and I had unlimited access to their fleet of boats. Then I went to a local yacht club that has weekly "social" sailing races. Skippers are always looking for crew. Our YC holds a "crew search" event every spring to match up skippers and people that want to sail. They also have a free juniors program targeted at young sailors such as yourself.
Eventually we bought our own boat and obtained our ASA certifications because we wanted to bareboat charter.
`99 Beneteau Oceanis 352, #282 WiTCHCRAFT
Sailing Lake Michigan and the Great Lakes