To start a sketch, we need to have a part file open. Then, we can follow these steps to get into the sketching mode:

1. Select one of the default sketch planes: Front, Top, or Right.

2. In the CommandManager, select the Sketch option, which is marked as 2 in the following screenshot. This will open up the Sketch commands category, which will show all the commands related to sketching. 
3. Select the Sketch command, which is marked as 3 in the following screenshot. This will allow us to enter the sketching mode. When we're in the sketching mode, we can apply different sketching commands, such as the marked Simple sketching commands:

Now that we are in the sketching mode, we can see multiple sketching commands on the command bar. This includes commands for sketching simple shapes such as lines, rectangles, circles, polygons, arcs, and others. Let's go over these commands in more detail. However, since we are already in the sketching mode, take some time to randomly click on those commands and try them out on the canvas.

There are two alternative ways to start the sketching mode, as follows: 

• Select the Sketch command first and then select the sketch plane.
• Click on the Sketch shortcut that appears when you click on one of the planes. The following screenshot highlights this shortcut:

Before we start applying these sketching commands, we will discuss what it means to define a sketch.