Computer Help. My computer does not start and when i push the start butten there is nothing on the

Question

My computer does not start and when i push the start butten there is nothing on the screen even if i wait for an hour.it was fine when i shut it downi didnt shut it down by the off butten i did it the right way by going to start and clicking turn off.And i have my homework that is in the computer and need it by this monday.