Alright lemme explain it to you then Shiann.
Script path is the directory in which Mys is installed on your server. If you use your root directory/public html, leave it blank. Otherwise change it to the name of your subdirectory. A good example is Mys v1.2.1's demo site:
http://www.mysidiaadoptables.com/mys121
The domain name is mysidiaadoptables.com, while the highlighted part is script path.
The table prefix is quite easy to understand, if you see your database tables all have the first several letters to begin with, this is your table prefix. Table prefix is usually followed by the underscore symbol. A good example is adopts_adoptables, adopts_owned_adoptables, adopts_users. The table prefix here is apparently adopts_. Keep in mind that you can name your table prefix to anything you like, and there's no need to change its value at all.