I simulated several 3d wings. I want to plot the spanwise lift and drag distribution. How can I do this in Fluent?

Use field View to perform this task.

What you can do is generate spanwise cuts of your surface, plot the CP values in X-Y Plot, and then manually integrate the pressures along the chord for each spanwise station. Sounds like a lot of work - but it is pretty much just writing a short Excel spreadsheet.