I haven’t seen any wide agreement on the best “minimal” (empty) theme to customize. If you are decent with code and really want a blank theme, you can read a tutorial (sorry I don’t have the link) that tells how to make your own theme from scratch.
Otherwise look around the link Moshu gave, and find a theme that starts off the closest to what you want, and start editing it.
I disagree with the idea the default theme is the “worst”. There are FAR more complicated themes than that. But Kubrick (the default) is notoriously tricky and has a few quirks that make traditional answers not apply. However it isn’t impossible to edit, in fact it isn’t very hard at all. When I was new on WP, I immediately hacked the heck out of the default, before anyone told me it was a challenge.
The main reasons Kubrick is considered tricky are: Kubrick uses image files for the background instead of pure CSS; and some of the CSS style is in the Header (header.php I think) near the top, and not in the CSS stylesheet (style.css I think), which is unusual. Once you know that, Kubrick is easy to edit like any other theme. Go for it.
Hope this helps
