This is where I see that something is wrong. When I got to my dev site http://www.pvcdev2015.dev/wp-admin and try to log in, it redirects me to the regular log in page of my regular site (plymouthvision.com): <a href="http://www.plymouthvision.com/wp-login.php?redirect_to=http%3A%2F%2 Fwww.pvcdev2015.dev%2Fwp-admin%2F&reauth=1" target="_blank">http://www.plymouthvision.com/wp-login.php?redire..." target="_blank">Fwww.pvcdev2015.dev%2Fwp-admin%2F&reauth=1

Any idea why this might be happening?

Thanks for your response here. When I log into my sandbox site I created here http://www.mydomain.dev/wp-admin it all looks the same as my regular site. Then when I choose a new theme it changes my live site also, so that's why I am confused here.

Every step I followed from the video on this page worked correctly. Is that how I should be logging into edit my sandbox environment from my local machine?

I am wondering if you can help me understand what's next here? Now that I have created my sandbox environment, how do I start making my updates? I am trying to update the theme/design of my site in the sandbox environment without messing up my main site.

ANY help would be much appreciate, I am very new to all of this so need any/all the help I can get!