To learn how to draw a heart shape in Adobe Illustrator follow the steps below and watch the video tutorial.
Create a new document. Select the Rectangle Tool (M) and draw a square (hold shift to constrain the shape).
Right-click on the square and select Transform->Rotate…
Rotate the square 45°.
Go to Edit: Copy and then Paste the square. Use the Direction Selection Tool (A) and round the corners to create a circle (click on one of the corners and drag it inwards).
Move the circle to the left top side of the square:
Go to Edit: Copy and then Paste in Front the circle. Nudge the new circle to the right. Select all elements and go to Pathfinder Panel to unite the shape.
Watch also the video tutorial: