Before starting learning I try to answer the following questions. It is important to ask and answer the questions in this order.

1. Why should I learn?

What is my end goal? Do I really need it? Are there other ways to achieve it?

2. What should I learn?

What exactly should I learn? Am I sure?

3. How should I learn?

Should I read a related book or find a mentor or ask a colleague to help?

4. How should I practice it?

Do I have a safe way to practice and make mistakes?