I can't open the Windows store and any other app for that matter for Windows 10. What should I do?

[Windows Central Question]

i can't open the windows store and any other app for that matter for windows 10

I just upgraded to windows 10 and when i go to open up windows end before nothing would happen. i finally started getting an error message telling me my trial period has ending that i need to redownloadi t. so i go to the window store and the first few times i tried it would briefly flash open and then nothing. now it says that i need to contact the administrator or reinstall. i have looked online and from what i found is everything tells me to go to settings. but my problem is the settings tells me the same thing as all my other apps that my trial has ended and i need to re download. if i didnt have chrome on my computer i wouldnt be able to do anything on it. i cant find a way to go back to windows 7 so i just tried to download 10 again. it took hrs like the first time but didnt do any of the installing after words so it didnt change anything. what do i need to do? please help