Why data structures are important?
The most important question that computer scientists think of is how their data is stored in memory (RAM)? Depending upon the design of the data structures searching time, retrieval time, deletion time and also updation time may vary.
We want our data to be accessible fast. That's why we designed various data structures. The most important ones are the following
Stacks and queues
Dictionary [HashMaps / Hash Tables]
Collection of few good problems that I think can help you build the problem solving skills. Try by yourself. If you can't solve the problem, then only check the solutions.