The classic exercise, in a starter version.

Kneel on the gym mat, and walk your hands forward - straight-arms - until they are at a distance from your feet which will place them level with your chest when you lower your body towards the floor, and just wider than shoulder-width apart. Your head should project beyond your hands when you lower your body towards the floor.

Support your body between your hands - straight arms - and your knees, and even in this position maintain a Neutral Spine Position. Lower your body to the floor by bending your elbows, using your knees as the pivot point, and keeping your body rigid. Hold for a second and then push your body back up, straightening your arms,  making sure you keep your body rigid and maintaining your Neutral Spine Position.  Don’t over extend with your arms and shoulder blades when you push up

Do not let your head or body touch the floor until the exercise is over.