Why did my HDMI port stop working?

One day after I used it to watch a movie, I turned it on and the screen wouldn’t appear on the tv. The Xbox was on and working, but I had no visual. I changed the HDMI cords and switched TVs but nothing worked. I have come to the conclusion that the HDMI port is broken. I don’t know what to do as I am not very skilled in this department. Also, the power button has lost its click and won’t turn on the Xbox. I think that broke off too. What can I do?