Here are some thoughts on getting started, not in any particular order.
Get a buddy
You need to have a buddy with you each time you meet with a merit badge counselor. This buddy can be another scout, a parent, a sibling, a relative, or a friend.
It's also a good idea to not kayak alone.
Find a merit badge counselor
Your scoutmaster can help you find a merit badge counselor. He should have access to a list of merit badge counselors in your area.
Get the Kayaking Merit Badge Booklet.
The booklet has the list of requirements and lots of great information on paddling your kayak safely and effectively.
Your troop may have a copy of the booklet. Some public libraries have the booklet. Or you can purchase yours from your local counsel. I bought mine at scout camp last year.