Enable the 3D sketching option to do things you can't do with a 2D sketch, such as sweep and snap to points.

Here are some fundamentals for creating a 3D sketch in Fusion 360.  We will look at:
-Moving points of a line off of a work plane
-Dynamic 3D sketching using the XYX UCS guide
-Creating a 3D sketch with a reference body
-Using a point as a reference for a 3D sketch

Please note, if you use reference geometry to help you create a 3D sketch, but you don't want that reference geometry in your final model, expand the Bodies in your Browser and turn off the light bulb next to the reference geometry you don't want to see.