I'm on Windows, but think I figured it out! Turns out on launch, the program window isn't expanded all the way and always launches slightly minimized, so it hid the control key list I needed to learn certain stuff. This fixed my square grid/select issue, and also since the 3D Ortho button was hidden by this, that's why I couldn't save my stuff. So it was a skill issue on my end, but hope this helps somebody! Thank you for your time!