I downloaded Blender onto my Mac laptop, but it will not open. When I try to open it, I get an error message that says, "'Blender' can't be opened because it is from an unidentified developer." I'm not sure what to do to get it to open. :/
This is a Mac problem, not a Blender problem. I am a fellow Mac user and have dealt with this myself.
You probably have an error something like this:
After trying to open an application several times, you should see the above image, which also includes an Open button. Click that. You should not see the error again unless (occationally) when you restart your computer or redownload Blender. You can also attempt to open the application by right-clicking on the Blender icon in your dock and selecting Open: