I am going through the tutorials but the website is built, I am updating material without a problem. I cannot find where the templates are I need to add a category. Previous web guy renamed a couple of positions and I don't know what file to change?

Hi and Welcome
No you do not need to download the site to your computer but it is important to have a backup of the site and database.
What version of joomla are you using?
Regards

I am using 1.7. Our website is www.blossomalive.com

I did download a backup copy onto my computer.

Thanks for your help

Hi and welcome, Cornerdnr!

You should update to the latest 2.5.4 as soon as possible. Your Joomla version has a major security issues and a lot of bugs that have been fixed in 2.5.4.

Here's how to update from 1.7 to 2.5: www.ostraining.com/blog/joomla/how-to-update-joomla-17-to-25/

Once, you've updated, could you clarify your question please? Are you just trying to add a new category for articles? If so, you can do that from admin area >> Content (top menu) >> Category Manager (sub menu).

Kind regards,
Nick