That depends on where you go, because numerical control is a big category. There are many softwares used in it, such as UG, mastercam, powermill and so on.

Different softwares have different functions, so they are different.

If you want to develop in the direction of mold, it is recommended to learn UG and powermill, because UG is good at drawing and is mainly used to dismantle copper molds. Powermill means that the tool path is safe, so the combination of the two is efficient and safe.

There is mastercam, if it is developing towards some simple parts processing, then this software is recommended. When there are some loopholes in route selection, they are all efficient and simple.

I hope it will help you in your choice.