My AOC monitor says "No Signal" despite being connected to my PC.

So basically I've never had a PC before. I know that my PC and monitor are correctly conncted, however when I turn on my monitor (and PC) my monitor says "No Signal" (The monitor is a AOC gaming monitor with 260hz). There are five small buttons under the right side of the screen, on the right theres the off and on bitton, and on the left theres a button that let's me pick out HDMI 1/2 or DP. No matter which one I pick my monitor says " Changing this setting may increase power consuption. Would you like to proceed?" and then "Yes /No" however, I cannot pick yes, and it automatically turns said screen off. What am i supposed to do now? How can I fix this?

(Please keep in mind that english is my third laguage, therefore I might have some grammatical errors or typos. Also I don't know much about PC's, I just wanted to play some games :( )