Congrats on your new boat. Taste test the water. Have a way of rinsing out your mouth if you think it might be nasty water. If it is salt
that means that you have a hull leak. If it is fresh then that means you have a port or hatch
or lifeline stanchion base or chainplate or u-bolt or maststep or whatever else might not be bedded properly.
Freshwater in the bilge
is not good because it will rot
the bottom of any plywood
bulkheads or cabinetry. You need to get those holes bedded properly. Saltwater on the other hand is an indication that you have a leak in the hull.
You have a swing keel
with a winch. If the winch works really hard and not very well then you might think about replacing the whole winch. I think you can buy stainless boat trailer winches for pretty cheap
. If the handle turns and the drum doesn't then it is going to need some fixing or replacing.
Your galley sink should have a drain in the bottom of it that drains into a big plastic jug or out through a thruhull. If it has a big plastic jug type drain then just replace the jug and dump it each time it gets full. I don't believe there is any restriction on grey water dumping in bays but it would be good to know your regulations
in your area.
Start with your library and look up sailing, boating
, boat building, etc.. You'll be able to find a lot of the answers to your questions there.