how can i simulate a glider descent ?

Maybe using Simulation Flow.

I think you need a series of studies to get all of this info.

In general, the glide path will depend heavily on control inputs and environmental conditions. But you can readily characterize your designs glide ratio, which is very likely what you care about, and which is theoretically equal to the lift/drag ratio. The L/D ratio should be easy to get out of a FlowWorks study.

To get stall, you might do a series of studies at different speeds and angles of attack to see where stall occurs.

Max speed should shake out of the drag results.

I'd suggest using X-Plane.  You can create your glider using cross-sections of both fuselage and wings (tail too).  X-Plane then can display drag & lift for all phases of flight (i.e. dive/glide descent from high altitude to stall conditions)

I wish there was a way to export solidworks into X-Plane, but I'm not aware of any such path.