The error mesages are saying (as you have probably noticed) that the PowerGallery set-up can't find the 'properties.php' file where it thinks it should be. It is looking for it at properties.php which returns a 'Not Found (404) error if you navigate there directly.
The surest way to sort things out would be to upload the complete contents of your downloaded PowerGallery folder (PowerGallery 1.0.0 Complete Files) into a new folder in the root directory of your remote site, not into the root directory itself. Call the new folder whatever you like (i.e. gallery).
That should allow you to begin the install process as described in the Getting Stared Guide
You will need to have details of your database connection (localhost, database name, database username, database user password) ready to enter during the set-up process. You should be able to create a new database or find the details of an existing database from the control panel of the site that you are uploading to.