A target curve is the tonal balance your room correction aims for. Choosing one is the biggest single decision after the measurements, and a flat line is rarely the best choice. Read these in order, then download a curve to try.
Guide 1
What Is a Target Curve?
Why room correction needs a target, and why flat usually sounds thin.
Guide 4
Applying a Target Curve in Dirac Live
Loading a curve file and applying it to your speaker groups.
Using another system? Audyssey, ARC and YPAO have their own target controls, covered in the Audyssey, Anthem ARC and YPAO guides.