Interpolation of Vector Points based on Borehole point data

hello,

I am working with borehole point data (x,y) in western New York and trying to create a subsurface layer based on the depth values to then be used in 3d subsurface display of the top formation layer. However I am unsure of the best way to create this layer, my thoughts have been so far to use an interpolation method but I am unsure of which one since I have very few points for a very large area. It would be very helpful if someone explain in simple terms the best method to create this layer.

Thank you!