The same html can be made to appear differently depending on what box it is inside of. For example you can have a generic h3 tag but then change that tag to main h2 or footer h2 to change the look in those locations. This would be change on the CSS, not the HTML.
Multiple differnet symbols can be put into the page using the proper code for it. These codes can be found online.
Span tags can be used to change a specific bit of text within a line. Span is a tag that you can use as a box or to stylize type. It can be used anywhere to help you identify or make parts of text stand out. For example you could change the background color of a word or the color of individual letters within a word. Multiple spans can be used at a time to make it however you want it to look.
You can change the look of links on you page by using the tags (a) within your CSS. The multiple differnt looks you can change are when the link is visited, when you hover over it and when you click on it. These will look like this in the CSS...
a{ }
a:visited {}
a:hover {}
a:active {}
These need to be in this order for them to work.