Help! (I CANT FIGURE IT OUT)

I created a website and Im trying to add ads that randomly pop up during usage. My question is… where do I find people willing to pay out per click? Or let’s say they have to finish watching an ad video to keep using the site. Please I have a month trying to figure it out.
Where can I find these?
What are they called?
Is there a AdMob alternative but for sites?