Oops! Not enough coffee yet- didn't read your post right, that you had tried the panel. Should be able to use the goodies tab to set up password protected directories though. Am not sure how to change default home page (index.php, index.shtml, index.html... should work as is) from the panel, but you could put the following line in your main directory .htaccess file:
It may be better to just rename your main page to index.html(or index.php, etc.).