Help with identifying question types for USACO Silver

General Questions
#1

Even though I understand the solution to the question that I have done and can recreate them, I struggle with figuring out what new questions want me to implement, such as whether to use graph theory or some other algorithm.

Is there any way to think through these questions to know which strategies should be used?

#2

Going through lots of problems and spending time understanding why a certain technique is used and how you could come up with it independently should suffice