fully3:
Not sure where the php admin is . what does php stand for ?
Okay... you have a bit of learning ahead of you.
The features I described earlier are fundamental webmaster tools and my advice now is for you to find some tutorials on the internet that explain these features, and how they work.
php, to put it basically, is a scripting code that works (generally) in conjunction with a database.
It enables DYNAMIC content to be called from a variety of places - the database, an image file, a url, a piece of text, etc - and be cobbled together into a html page which is then visible in a browser (such as Internet Explorer).
Zen Cart functions on the principles of php scripting, operating in tandem with other features - mainly a database that runs off MySQL.
phpMyAdmin is a tool to MANAGE and CONFIGURE this database, and while it is unlikely that you will ever need to do detailed management, when things go wrong (and they occasionally do), it is helpful to at least understand the principles of what makes your webshop work.
If you are very new too all these concepts, buy the new book (advertised on this website) as it will give you a good grounding in zen cart. This will make understanding the more complex stuff much easier when you need to start making detailed changes to your webshop.