Thank you so much for using our theme Corporate Plus. There is no any options to show/hide the powered by text on the free theme where as you can show/hide it easily on the premium version of it. In place of that text, if you want to put another text, we will help to put on the premium version of theme with customization.
If you are interested on pro theme, we will mentor to use the pro theme features too.
All the themes are GPL and you can customize the theme as per need. If you want a simple options for it, you can use pro version. We recommend to use pro version because it have lots of additional options and features to customize your site. But, Child theme is recommended to customize theme.