After starting to learn DSA in Java and getting some hands-on experience after solving a few leetcode problems. Here's what I have learned about how to use leetcode effectively as a beginner:
After completing the lecture, first approach easy to medium level questions and don't spend more than 35-40 minutes on a single question on leetcode.
If stuck on any problem, take hints from the hints section or discussions and then try to solve it again.
Bookmark that problem, where you got stuck, and then try to solve that problem after 2-3 weeks, repeat the same if you're still unable to solve it.
How to approach a problem?
Firstly, try to solve a problem using the worst complexity with brute force. After solving, then try to optimize the code.
For each topic, make a note about the patterns and approaches used to solve a particular problem (very important).
It is important to make a note for every topic, what type of method is used and what kind of optimisation is used to solve a particular problem for running effectively and satisfying time and space complexity making it effective.
You can also refer to DSA sheets made by professionals for better understanding.
Practice DSA consistently like 2-3 hours a day, it depends on the person and dedicate the rest of the time to making projects, Development, Open Source and other important things.
Don't forget to comment on how many problems have you solved in Leetcode.
Feel free to connect and ping me on any social media platform.