Some boats don't have a big enough wake to be 65' out there and still get the vertical pop that you want because you have to go a little faster and that flattens out the wake. Just mess around with the length and ride where you are comfortable. But never assume you like it where you're at, even if you've been riding at that length for a month. As a beginner, fins don't matter that much, except that you'll be better off with a bigger fin, but once you can get up and jump all right, you should not use a big fin. The point of a fin in the front being smaller is so that you can come back from fakie easier.
Big fins track better.
Some poeple use a 3 fin setup, but don't do that unless you plan on riding in the ocean in the surf. It makes it so much easier to float while waiting for the boat to turn around when you wipe out. Also you never know how hard your head might hit the water if you wipe out. So wear one, especially if you're beginning, it could save your life. Wetsuits Wear a wetsuit in colder water of course.