Drupal 6.x

Like most noobs, I am still wrapping my head around taxonomy. I have the following question.

I would like to have a site with a section entitled 'Articles'.

Inside it I would like to several categories, into which I can place articles.

I would envisage the left sidebar menu to exist and expand as follows:

--'Articles'
----o Catgeory 1
----o Catgeory 2
----o Catgeory 3

Some articles might be a member of 2 categories.

I would like an RSS feed of the most recent articles that I can sydicate to my users.

My questions are:

Hi,
First time drupal user but that's no excuse for what i have just done. I accidentally logged myself off whilst I had set the site to be off line. How can I log back in or make the site live again?

Thanks

I was wondering if anyone had ever tried to organise the modules section of the site.

It strikes me that when a new (or even semi-experienced) user is looking for modules:

Is there any module like NiftyCube or CurvyCorners for drupal 6.x ?
Or there is an other way to create round corners for my menus mainly.

thanks in advance

I seemed to install drupal correctly but now whenever I go to any page I have a long list of errors appended to the bottom of the pages. I am using siteground as my host. Here's what it looks like:

Warning: Couldn't fetch mysqli in /home/dogsonth/public_html/includes/database.mysqli.inc on line 323

Warning: Couldn't fetch mysqli in /home/dogsonth/public_html/includes/database.mysqli.inc on line 108

Warning: Couldn't fetch mysqli in /home/dogsonth/public_html/includes/database.mysqli.inc on line 122

Is it possible to generate customized, tabular reports on customized content types, which can then later be printed, or clicked on to access the specific content? I think what I'm looking for is a search function with customized search returns in a table format that can be drilled down into if desired.

Thanks for any help!

-George