The closest angle you can sail to the wind is on the edge of the no go zone.
This point of sailing is called close hauled.
You should have the sails pulled in tight, with the centreboard pushed fully down to
prevent side slipping.
And by probing with the tiller to find the point where the sails just start to flap,
you are on the edge of the no go zone.
Close hauled is the point of sailing you should use if you want to sail towards the wind.
Changing sides is called tacking and is the subject of another video on this site.
Sailing on subsequent close hauled angles, tacking between them, you will eventually
end up at your upwind destination.
Together, a series of tacks is
called beating.