Open the software's tool bar and find the ellipse tool. It will feature an icon of an oval.
Click on the tool with the left mouse button.
Click on your work space where you want the left side of the oval with the left mouse button.
Hold down the left mouse button while you drag the mouse to the right. The farther you drag the mouse, the larger the oval will be. To make the oval narrower or fatter, drag the mouse back and forth, without letting go of the left mouse button, until you get the size you want.
Press "Control" and the "Z" key to delete the oval and try again If you make an oval you don't like. Or click on the "Pick" tool (this tool has an arrow for an icon) and drag the oval's sides until they are the size and shape you like.