All the things you mentioned are important. If you only do exercises but don’t look at other people’s solutions, you get better with the tools you already know. But you won’t know the limits of your knowledge.
When you finished an exercise, go and look at other peoples solutions - try to understand what they did and then try to use that way on a similar problem yourself.
Trust me, if you constantly see people using some way you don’t know, you really want to figure out how to do it that way yourself 