Creating shape around line

I am not proficient with meshes either… I think for any professional my definition is kinda cringe. What I would like to know though, is how you solved this problem, using boundary surfaces? BoS it is nurbs, and trying to convert it into mesh, would give vertices mismatch, like here - Join the vertices of two different meshes? - #12 by johnharding
I dont know how to solve such problems yet.