While I certainly agree with mysnakesau's advice for new keepers (such as yourself), I've found that keeping young snakes in click clacks isn't essential. However, some serious though needs to be put into the enclosure design, and the snake's temperament needs to be assessed. If your snake hides a lot, then perhaps putting it into a large enclosure isn't a good idea. However, if your snake is always out and exploring, then maybe a bigger enclosure isn't out of the question.
As you can see in the photos, this is how I keep my six month old coastal carpet, and have kept him like it for several months now. I couldn't get a proper heat gradient in his click clack, so moved him into this enclosure. His feeding and shedding has not changed at all, but his temperament has become less aggressive (for whatever reason I do not know, and he is not handled very much at all). I always see him out and about, and that's him happily basking in full view of everyone.
Not trying to undermine mysnakesau's advice, just trying to point out that keeping snakes one way isn't the
only way.
As for what snake you should buy, many of Australia's pythons are easy to keep. The Antaresia complex (spotteds, childrens, etc) are very small and easy to keep (my first snake was a spotted), and are easy to breed, but getting hatchlings to feed is usually somewhat difficult. Coastals and bredlis are all around good snakes. Get to a nice size and aren't usually aggressive. Diamonds are nice snakes, but need to be kept in certain ways in regards to temperatures and cooling to prevent early deaths.
Water pythons are nice snakes, but many a snappy. Olives and scrubbies probably aren't the best, as they get pretty big and could do some damage to you, and scrubbies in particular are known to be aggressive. Womas and black- headed pythons are also good all around snakes. Check out this link for a more detailed look:
http://www.southernxreptiles.com/Article PDFs/road_testing_lr.pdf
One very simple word of advice is never buy a snake expecting that it won't bite.

Owning snakes means that a some time, you
are going to be bitten. But other than that, have fun with reptiles
Baby snakes should not go into large enclosures. I know setting up the enclosure is the most fun part and you can't wait to see your snake in there, happily wrapped around branches, but babies need to start off in click clacks - these are little tubs just big enough for a hide, water bowl and a basking place for them. By the time the snake is about a year old he should be well settled to be able to live permanent in an enclosure. When I moved my bredli's into enclosures, I gave them everything out of their tubs so that they are some familiar smells with them and even their tub if it fits in, let them have it until they are happy to come out. Had no problems with them, appetites didn't change, their temperament didn't change and they actually look comfortable.
Large homes for little snakes is rather frightening to them. He doesn't know that you aren't trying to eat him or that there are no predators in their enclosure. So he may be rather defensive and/or hide all day long. They are secretive animals and most often be happier in confinement rather than spread out for all to see. A book I am reading tells of a study that was done on diamond pythons. They caught the diamonds, microchipped them with tracking devices and released them. In a two period most of their snakes barely moved. None moved further than a few yards while some remained in same spot. This was good reading to help me get over the thought of squashing my snakes into too small enclosures.