As a beginner, focus on performing the following 5 basic bodyweight exercises perfectly before expanding your workout.
1 - The Sit-Up
Very simple, super basic, the sit-up works multiple muscle groups. Lie down on your back, with your legs slightly bent and feet together. With your hands on either side of your head, slowly raise forward. Return to your starting position.
2 - The Push-Up
Lie face down on the floor. Place the palms of your hands on the floor about shoulder width apart. Keeping your back and legs straight, push upward until your arms are straight. Pause and return to the floor.
3 - The Lunge
Stand with your hands on your hips and your feet shoulder width apart. Step forward with your right leg and slowly lower your body. Continue until your left knee is nearly touching the floor. Return to the starting position. Repeat with your left leg.
4 - The Plank
Get into the push-up position, but rest your body weight on your forearms rather than your palms. Clasp your hands together and rise up on your toes. Keep your back straight. This bodyweight exercise is so named because your body from your ankles to your head should be as straight as a plank. Hold for 30 to 60 seconds.
5 - The Squat
Stand with your feet shoulder width apart and your hands on your hips. Keeping your head up and facing forward slowly squat down, bending your knees. Pause at the bottom then rise up, keeping your back straight.
Those 5 basic bodyweight exercises work your entire body when combined into a strength training routine.