Hey Dennis, welcome!

The only reason to download VWD Express and the StarterKit is if you are planning to write some code either to develop your own custom module, or modify  an existing core module. It sounds like the customization you are attempting to do is more in the area of skins and the look-and-feel, in which case there's no reason to go the Starter Kit route.

Skins and containers often have their own stylesheets. Be aware that your web site actually contains many stylesheets, portal.css, module.css, skin.css, container.css, plus possibly some custom ones that came with the skin you are using, so I would suggest the following...

Open your skin in the browser, then view the page source .. search the source for all the .css files that are included in your page. Take special note of the order in which they are loaded as in stylesheets, last one wins when styles are defined multiple times. You may have to modify the .css files externally ( ie: not use the stylesheet editor built into the product ). 

There are also some good inspection tools out there that might help, such as the IE Developer Toolbar ( a quick google search should find it for you ), that allow you to open a web page, then click on an item and it can show you which style ( and which stylesheet ) is being applied to that particular item.

That should help you identify which .css file and which style to edit to make the changes you want to. Also, be sure to refresh your browser after making .css changes as the styles are sometimes cached and won't update automatically

Unfortunately, every skin is not created equally :).. packaging is not always the same, you will need to take a look a the skin package you downloaded. I assume it's a .zip file, is there a readme file in the .zip? maybe there are some specific installation instructions that you need to follow.

When you upload a skin to a DNN web site, you upload a skin.zip file. Inside that .zip is the skin file itself (either a html or ascx file), most likely a stylesheet, skin.css, and any other resources like images, etc that the skin needs. The DNN installer extracts the files from the .zip and writes them to the proper location in your web site and 'registers' the skin in the DNN tables.  The same holds true for containers that may be packaged separately in a container.zip file.

If you downloaded a skin package, it may contain multiple skin packages and/or containers, so it's *possible* that you need to unzip the package first on your local hard disk and then upload/install the skin and/or container packages.

This is just conjecture since I don't know what skin package you downloaded or how it was packaged.  If there are no installation instructions with the skin, either on the web site where you downloaded it or inside the package itself, you might have to contact the author of the skin for some guidance.