If you remember the lesson on
keyframe and in-between basics, the next thing we draw wont be the next frame in the sequence. Instead you should pick a key point; my animation is going to show my character making a short turn and then moving his arms a bit, so I picked a key point showing when the character is facing fully forward after turning from the starting position.
Draw that key point, using the drawing beneath as a reference for proportion and position. Itll take some practice, but youll get pretty good at eyeballing these things as you go along.
Once youre done, you should have your first two primary keys.