Yep, matches are just for fun. A sanctioned match is important though, I believe new clubs must hold a certain amount of matches in a certain time frame before they're allowed to hold regular dog shows. Sorta like a trial run to make sure the club can do everything needed to run the event and take care of paperwork appropriately. Also already established clubs will hold matches in the evening after the show, and I have a feeling they are a good money maker for the club since they already have all the equipment and everything taken care of for the weekend.
Matches are great for training puppies. It takes time to get used to a crazy show atmosphere, and it will really help puppies get used to the ring procedure and being examined by strangers. (even in some not so nice places!) lol A couple of specific things that are usually harder for puppies to get used to is standing still while strangers are touching you on the table, and gaiting nicely (trotting, not galloping around like a banshee) with other dogs running in front and behind them. lol These are things you can't simulate so well at home, matches are a great way to see how naughty your puppy can be so you know where to concentrate more of your training. The hopes are that by the time you're spending the big bucks for the real shows, that your dog has an idea of what it needs to do and will be somewhat compliant so you have a better chance at getting those points. Like Lisa said, since it's a sactioned match, they will be doing everything like it is a real show and it will help you and your puppy learn the procedures.
Of course if you have an opportunity to go to conformation classes, that's a nice help too! Sometimes you can overkill on the training and make things worse, but in general, the more practice the better.
There are 3 kinds of chains people usually show in, the "snake" chains (they kinda have thicker/closer together links), jewelers link chains (like a necklace), and regular links like a standard choke collar. I would get a fine a chain as you can in the size you need. I usually use a 16" chain by the time they're old enough to show, but some people use a 14. I think for puppies I have a 12", but I usually use a nylon show choke for the little ones, and before that a nylon martingale. The jewelers link is very pretty, but it kinks easily and seems to pull out hair more and be "itchier" for the dogs. I've used them as well as the snake chains, but have reverted back to the regular type chains these days. Most people show in the chains because it gives more control than a martingale and also helps keep their noses out of the ground better.
Good luck with Zoni, and let us know how she does!