Catalina, Beneteau, or What ?
One of the problems with answering a question on the internet of this nature is that an answer will sometimes sound like a put down when the writer has no intention of putting the other person down. I have editted this a couple times and I can''t seem to get the tone to be what I would like it to be. I, in no way, intend this to sound like a put down. What I want to say is that we all had to learn to sail through one process or another and we all end up achieving some level of knowledge. Some of us seek to really understand how to safely and comfortably handle a boat in a wide range of conditions and other simply want to know enough to go sailing and get back to the dock. There is no one right way to learn to sail and learn to safely handle a boat, but there are ways that are more difficult. I would suggest that if you really care about learning to sail well, meaning developing more than the rudimentary skills required to get a boat in and out of a slip for a sail, the boats that you are considering are far and away too big a boat to learn on.
Beyond that, it makes no sense at all for a beginning sailor to purchase a brand new boat. Properly outfitting a new boat is a major undertaking, requiring a lot of work and a lot of money, and one that requires a fair amount of knowledge that a beginner is certain to lack.
I cannot strongly enough encourage you to consider starting with a smaller, simpler boat, and developing skills and preferences so that you will then know what you want when you move up to a bigger boat.
Which brings me to my next point. The Beneteau 393 and the Catalina 350 are extremely different boats from a use standpoint and represent somewhat different philosophical approaches to yacht design. With all due respect, your narrowing the choice to just these two designs, suggests that you really do not have enough experience to understand what you want out of a boat. There is nothing wrong with that, we all had to learn sometime. BUT $185,000 is a very big budget to buy a boat and there are all kinds of wonderful boats out there in that price range that may better suit your needs once you learn enough to know what they are.
To answer your original question, based on my own experience with both Beneteaus and Catalinas and a fairly large number of conversations with marine surveyors, I generally consider the design and build quality on the Beneteaus better than on the Catalinas but there is bound to be a large variation in opinion on that.