Hi there, in order to make css alterations you'll need to download a firebug (www.firebug.com) and find the ID/Class for the item you want to apply the new css to. There are many videos on youtube which will advise you on how to use firebug. You're looking to edit the css, not the html or php.
Unfortunately as you're using the free version of the software we're unable to assist you in this process or the editing of any css or customization, you'll need to learn how to use css to make the adjusts yourself.
However, a great entry guide and overview of css can be found here http://www.w3schools...css/default.asp which will help you learn the fundamentals.
If you're looking for a higher level of support for Pagelines then take a look at upgrading to our Pro/Dev edition which is available with a Plus Membership :-)