election voting

Okay this is a stupid question I KNOW, but I know nothing about voting and how it works as I havnt really taken it seriously until lately. This is a really stupid question for my age LOL but, I can't get to the polls until 7, and I'm confused as to how my vote gets counted if today is the day the next president gets elected. They are open until 8 and idk 7 or 8 is kind of late. Is the poll on a computer? When do we find out who won? So confused. Please somebody enlighten this dummy over here lol 😂