1) I played around the admin and created multiple websites and stores which I don’t want and I don’t know how to delete.
there is no delete button even in the edit mode. How do I start over from scratch? How do I start with a clean Database?
A: You should be able to delete stores. In backend: System -> Manage Stores -> Click on a Store Name (not Website Name or Store View Name) -> click ‘Delete store’ button. You may also be able to delete websites as well (I didn’t try it). Please note I’m using v1.1 beta.
2) I created a few categories but they don’t show up in the front end.
A: You’d better take a look at some screencasts at http://www.magentocommerce.com/media/screencasts . Those screencasts are very helpful guiding you setting up your online store.
3) How do I change the Logo and the colors of the website?
A: You can check the URI of the default logo, which is something like http://magento.dy/skin/frontend/default/default/images/logo.gif. It’s very easy to locate the logo file on the server from this URI. For colors, you can get those CSS file location by viewing HTML source code. You may not be able to do it by yourself if you don’t know HTML well enough.
Hope this helps. Good luck.