I want to create a website that looks open and clean, just some basic headings at the top of the page for people to click on, and also an online store. What would be good for that? I tried Joomla for a bit, but it seems very "clunky" with so many tables and menu buttons everywhere.
you can try CMSMadeSimple or TextPattern for simple websites. But if you want to make an online store then I suggest you use Drupal or Joomla. They have nice plugins.
Joomla is the best around. You find oscommerce ( online shopping cart ) modules for Joomla. It takes a while to learn but once you know the basics, its fantastic
What type of shop system requirements are you looking for? Is this for downloads only or are you shipping physical items?
Be more patient, with all the "clunky" tables and menu's u can do many things. Just be a little patient and you will see that joomla is the best CMS ever made. The most important thing is there are alot of extensions free online. If u still want to use other CMS you can go here, http://www.opensourcecms.com/ here you can try first and change everything through admin without worry that the web owner going to scold you. More info fell free to check this xt3ch.com/portal
demos of most available at www.opensourcecms.com - try to browse a few of them. Easy, clean, secure and nice..? I recommend e107 ... filter out easy and drupals the right way to go.