Fast lane:

Squats

Start with your feet slightly wider than your hips.
Keep your chest up and your spie in a neutral position.
Tighten your core as you sit back like you’re gonna sit back in a chair.
Try to lower yourself until your tights are pair level with the floor. Also make sure that your knees stay inline with your toes.
Now push your feet to the floor to come back to your starting position.