Advice for a beginner

Hello everyone! As the title suggests, I have just started out with competitive programming. I am familiar with concepts like arrays, recursion, 2-d arrays, sorting or strings and can solve problems with them, but advanced topics such as dp or greedy are unknown to me. I solved 12 problems from the beginner section and 10 from the easy one.
I would like to ask a few questions:

  1. Should I go with the beginner or easy section?
  2. Is it a good idea to solve all the easy problems, for example, and then move to the medium ones?
  3. For learning new concepts I am currently using this: Learn Data Structures and Algorithms | DSA tutorials | CodeChef. Is it good or would you recommend something else?

Thank you and I apologize if these questions were answered in other topics!