A good place to start is this tutorial Caravel Orientation Tutorialor reading some of these FAQs and tutorials. This will also give you a pretty good idea what Caravel can and can't do. Once you have taken a look at the documentation we suggest you just experiment. Don't be afraid to play around with your site. Add content, add some styles, and just have fun. Once you have done this then you are ready to start designing your first site. For some examples of what type of sites are possible check out one of these sites:
These tutorials are here to detail and explain how to accomplish some of the more complicated features or processes in Caravel. If you can't find an answer to your problem here please check the FAQ or the Caravel wiki.