squats might hurt your spine only if your have previous back injury or your form is incorrect. Other than that, they are excellent compound exercises. if your shoulders hurt, Youre doing it wrong. Correct form is most important, just as in dead lift
With squats, proper form is vital. You can mess up your back, spine, knees, hips, a long list of injuries with a bad form. The weight needs to be distributed a certain way. Before you add too much weight, use lower weight. Look up form online and use a mirror to see how your body is aligned.