To change elements within a Curtain Wall, go into Edit Mode (which you have done, as the Edit Tag is visible in the upper left corner of your screen shot). Now you can select individual elements to change them. To change Panels sizes, drag the bordering Frames (adjacent Panels will then also be changed in size). To change the frame spacing of one row or column, make the Scheme
visible in the Edit Tag and then drag the Scheme lines.
You should add a Signature to your Profile (click the Profile button near the top of this page) with your ArchiCAD version and operating system (see mine for an example) for more accurate help in this forum.