Hello,
I am doing the primer on Python and relatively new to coding. I see there are 100s of codes. I just wanted to know if its a good idea to note all the codes in a notebook or copy on wordpad or any other way people remember every code?
Sumit
Don't worry!
Remembering or writing the codes is not necessary. Just practice these codes and that will make you comfortable with Python coding. If you have any queries, you can always refer to python documentation or post it here. Cheers! 
The best programmers don't have every API call memorized. They simply know where to to find the answer when they have a question.
For me, I resort to books. For others they may use Google or StackOverflow.
I choose books because it requires me to pick up the book, open it, read it, think about what I am reading and then implement what I read in the code I am writing. Other online resources I feel people just cut and paste. While this is faster, if there is a bug or outage the developer may or may not understand the code they copy and pasted.