To obtain a moment curvature curve for a giver section, first create the section in the section designer. Once you have created the section in Section Designer, click on "Display > Show Moment-Curvature Curve ..." menu command. This will show the M-C curve for a default axial force of zero (see below). You can generate the M-C curve for any axial load by inputting the desired load in the "P" field and clicking the "Refresh" button.

Neutral Axis Location

The neutral axis location is measured from the centroid of the cross-section, perpendicular to the line that is defined by the angle as shown in the figure below: