Dual monitor Disaster

I just bought a new monitor and tried to set up dual monitors. I had my new one as the main one but I couldn't see my desktop icons, I could only see my toolbar. When I switched to the old monitor and made that one the main one, I could see icons but nothing else. When I tried to make my new one the main one again, I couldn't because the screen to choose the option was stuck on the monitor which I couldn't see. My second monitor kept saying entering power save mode so I couldn't use it. So I had my second monitor display on the new monitor and I couldn't change my display back to the main monitor where I can go to the control panel and other things. I have an hdmi plugged into my computer going into the monitor and I had a vga cord for my old one and it kept saying entering power save mode. I also had another hdmi slot on my computer but that also came up with entering power save mode when I tried to use that too. So I just restarted my computer and now I can't see anything. I don't know how I can troubleshoot without seeing anything. My new monitor is black and when I unplugged that to see if the second one would show up, it was just black off the start up too. I'm so frustrated I need help. I know this can be confusing so ask me any questions if you need help understanding because it's kinda hard to explain.