Hi Vicki
I am Dave, an Independent Advisor, I will help you with this . . .
Open the Settings App (gear icon on your Start Menu)
Go to Update and Security - Activation
1
What version (Home, Pro, Windows in S Mode . . etc) of Windows 10 is installed on your PC?
2
In the Settings App, go to Home - Apps
At the top of that page, is a drop-down menu to choose where to install Apps from, is that set to 'Everywhere'?