similitude with C and Make

hi, I have two questions:

First, If I want to move the file called common.mk from its original folder to other folder, What are the changes I have to do to work properly? only “Basic directory setup for SDK” which is in line 53 or more changes?

And the second question is about cuda’s extension and C++ similitudes:
.c and .cu is similar because they have the implementation of functions.
So, .h and .cuh is similar too? is that correct?
for example, if I want to create a library with cuda what steps I have to follow? simply I define on .cuh and implement on .cu??

thank you!