Scrap the installation you did and start over.

1) create a database for your Zen Cart and make a note of the database name, user ID and password. If you've already created the database, just make sure you know the information I mentioned.

2) download a copy of the latest version of Zen Cart using the "downloads" link at the top of the page.

3) unzip it on your local computer

4) FTP all the folders/files to your website

5) run zc_install by opening a browser and entering http://www.yourdomain.com/zc_install

Follow the instructions from there.

Good Luck and Happy Zenning!