Hi, I want to create a surface between two curves. Please any one guide me
Thankyou
Make sure the curves you want to bridge with a surface are selected (your image tells me that they are). Then you need to join them into a single object. This is done by CtrlJ. The next step is to convert to mesh. Right click to pull up the Object Context Menu, and select Convert to -> Mesh.

Go into edit mode, and make sure everything is selected. If it isn't, press A. Now press CtrlE to bring up the Edge menu, or access it by clicking Edge in the menu bar near the top, then select Bridge Edge Loops.

Your two curves should now be joined with a bridge of faces. I used two circles in my images, but the workflow is the same.

As a side note, from the shape of your curves, I'm pretty sure you'll get self-intersections. This is rarely, if ever, a good idea. Such objects cannot exist in the real world, and even if you have a use case for self-intersections, beware that it may cause shading artifacts when rendering.