If you want to make the shift to functional programming then I strongly recommend that you first read this book:
This is the only book I know that spents a great deal of time educating you how to go from Object Orientated Programming and Procedural Programming to Functional Programming. @pragdave does an excellent job on making it click in our brains, can’t recommend it enough.
If you prefer video form, then he has a video course that does the same:
I have done both and that really helped me to let go away the old way of thinking about coding.
