In my opinion, Python is a brilliant choice for scientific computing and numerical analysis. Also, I think C++ would work, but it’s a complicated and difficult to master it.
C# is a very good choice for engineering software programming. It is also well-integrated with AutoCAD, Revit, MS Office, etc. It is also supported by some FEA software like SAP 2000. The latest can be useful in case you need to exchange models.