why cant i download photoshop

That is not an Adobe app, you may have been tricked into installing a virus. Where did you get it? Bear in mind Photoshop is not, and never has been, free - there is a free trial of 7 days only. Any site which tempts you with "free Photoshop" is just tricking you into installing a virus. They want your personal info, credit cards, your money and control of your computer, please take care.

Cloud Manager to install all programs https://www.adobe.com/ie/creativecloud/desktop-app.html
-https://community.adobe.com/t5/get-started/how-to-activate-your-adobe-software/td-p/9636861?page=1

Remember that after the trial period the account converts to a paid plan using the credit card you enter