Machine learning specilaztion course

Good morning everyone I have completed my first course in ml course but when I try to implement the code I can’t implement them as good as Andrew NG for ex I have to take alpha value as 0.000000000001 in order to minimize cost function which also I can’t get it below 5000 so I request all of u to please tell me what to do in order to make my practical knowledge good and how I can be better at implementation …
I am writing post for first time so please ignore any mistakes done in this post

What set of data are you using?

Have you completed all weeks of of MLS Course 1?

Yes I have completed all weeks of the course 1 and I am using data set from Google

General advice.
You code may have errors.
You may need to normalize the data set.

Thank you for the advice sir