The Database Connection file in PowerCMS 2 is named differently than the one used in PowerCMS 1. In PowerCMS 2 this file is created for you as you go through the Installation Wizard.
The WA_Globals file is named the same, but contains very different content that you should not have to touch at all.
You could either replace all the old PowerCMS files with the new files and run the Installation Wizard, or upload the PowerCMS 2 files to a different directory, but use the same database connection information to have PowerCMS 2 migrate your content.