I am a newcomer to boats in general and want to get into building scale boats. I have experience with planes and rc electronics and a basic understanding of woodworking. What would be a good first kit for me?

First off, you asked the same thing in two different areas of the forum. This is generally referred to as "spamming" and is frowned upon. That said, there are several kinds of "scale" boats. Are you talking ships(warships, cruise ships, sailing ships, etc), scale racing boats(offshore, hydroplane, crackerbox, etc) or did you have something else in mind? Something else you have to consider is what kind of power are you looking at using. There's gas, nitro, electric and wind.

Adding to what others have said are you talking about real building with woods kits or assembling prefabricated fiberglass or plastic "kits"?

I am interested in both. Sorry for spamming.

Available worldwide, but with zero woodwork involved unless you really want it, the Revell 1:72 Snowberry. A plastic display kit with plenty of conversion options and opportunities to think your way around them. Low cost, big enough to get both hands into, small enough to carry around. Electric power, which for me is the simple reliable option.
Modest performance is generally good for a first boat. Faster boats tend to throw their surprises rather suddenly, and water is an unforgiving playground. You can't walk over to get the bits back.

Then I suggest www.dumasproducts.com. They have a wide variety of products and prices. My first boat was their Huson 24 wood RC sailboat.

I would have to agree, something slower would normally be a better choice for a beginner. When I built my first boat, it was a Dumas nitro powered hydroplane. I had no idea on how much of a learning curve there would be to take that high performance boat and not only get it to work but, in the case of a hydroplane, work properly. While there are several high performance boats available, they do take a lot of work to get them to run. I don't know of any fast boats that will work right the first time. There's hours of building, balancing, testing and redoing to get them to the point of being runnable.
Along similar lines of the Snowberry would be the Tamiya 350 scale battleships. They are fairly large, have plenty of detail and options for more on a one piece hull. I know the Bismarck I built back in 1982 was actually set up to run with four "D" sized batteries and a three way switch. The way the rudder was set up, it would have taken some work to make it steerable but, that said, it was possible. I just didn't have the materials, knowledge or time to do so

a nice 1 boat is the artseania latina r/c hellen...decent length..has wood superstructure and deck..you can find older kits on ebay with the buld the hull yourself or the newerones have a grp hull..takes a dumas motor well and up to a 40mm prop..this set up gives good above scale speed if needed..motor mounting has like 2 to 3 inches above the keel so you can blue water sail

I'm not so sure I'd use a Dumas motor. What they have sold in the past(notice the past tense) have been old tech and not the newer and more efficient ones.
I'd personally check with Mack R/C Products. They sell boat kits, hardware and running gear for models. This would be for a more scale boat.
If you want more of a race boat, I'd contact Offshore Electronics.
The links to both are listed below:
index
https://www.offshoreelectrics.com