The number one most important thing for you to do to protect your back is to understand what core set position is.
If you take your hands on your waist and feel that bump of bone on the front of your hips just below your waist, that's the front of your pelvis. I want you to keep your fingertips there, then flip your thumbs up so that you feel the lower edge of your rib cage.
The distance from your pelvis to your rib cage should never change.
The situations where you risk getting an injury is if those two points get closer together or further apart.
Before you go to lift anything, check your core set position. Even in everyday activities, check yourself to see if the position you're sitting in or standing in is keeping those two points the right distance apart.
When you're sitting, are you slouching and letting these two points get closer together? When you're standing, are you letting your back arch and letting those two points get further apart? Both of those situations will set you up for a back injury.