Where are you located at? The dealership where you bought the jet ski will probably be the best place to do all of that if you do not know how and they should be able to give you pricing information on all of those things.
I bought the VX a couple hours away because they were priced better. I live in the Kansas City area and was trying to get ballpark figure. I have a call in for quote now, but just wanted to see if that was going to be reasonable price.
Take it too an authorized PWC Yamaha dealership close to you then. Just because you bought it elsewhere, does not mean your local Yamaha dealership cannot work on it or do warranty or maintenance repair work. I bought my jet ski's in San Diego but now live in Colorado. I just found out their is a recall on my Ultra 150 but I sure as heck am not going to take it back to San Diego for that. My local place can do that just fine so I will let them.