For a first wheelgun I heartily recommend a used Smith and Wesson.
Why S&W? High quality at a low price. Availability of aftermarket parts/grips. Value if you later decide to sell. Durability. The gun will last forever if not abused. High probability of finding a good gun in the used market. If a S&W isn't working right, people tend to get them fixed. If a Rossi isn't working right, people tend to get rid of it.
Why used? Low price for high quality. Great, timeless design. No grafitti on the gun. No lawyer lock on the gun. The new S&W revolvers don't compare.
I would also recommend a .38spl. Why? Cost. This S&W will likely not be your last. Once you get the bug and closs that bridge, they multiply. If you decide later you want to shoot .357magnum, you have a perfect excuse to go shopping again.
I would recommend a K frame, simply because most people end up loving them. It's just a great feeling frame size and lifetime durable in .38spl.
I would recommend a 4 inch barrel. It's the less expensive, and best all around length in a wheelgun. A six incher is a bit front heavy unless it's a pencil barrel.
Now, which is the best used S&W .38spl for you? That is a question only you can answer. There really are no bad ones, just different ones. My favorite is the K38, but I like the old M&P's as well. The M10 is a modern M&P, and the M15 is the modern M&P with adjustable sights. The N frame M27 is extraordinary in nickel, or especially in blue. It's S&W's Mona Lisa.
You should be able to find any of these guns in used but not abused condition for under $375. Probably around $250 you will find a nice .38spl. The M27 will be a little more worn at $375, but examples are available. I recently walked away from a nice M19-2 with a 4 inch barrel priced at $219. I have to stop somewhere!
Bottom line, go used, go S&W, and be knowlegable concerning pricing. There are regional variances in prices. Supica's Catalog of Smith & Wesson is the best resource I've found. Use
Jim March's Revolver Checkout to make sure you get a good one. Most used S&W wheelguns are great deals. Get a good one. You cannot pay to much, just pay to early. Enjoy your new addiction.