There are several different things to do in Minecraft - at least the way I see it. You start off by gathering the bare necessities - food, shelter, a bed. You start by breaking things down with your hand - well, your character's hand. You can "punch a tree" for wood and find some sheep for wool to make a bed, which you will need after playing for 10 minutes, because then it's night-time and the monsters come out! And when you first join, you are in no condition to take on the night forces! So, what can you do? Why, sleep, of course! If you sleep, they can't get you and the night passes in a few moments and then you can be off to play some more!
I will try to put up pictures of the things I have built after I make a section for Minecraft. That's what I like - building and farming and making red-stone contraptions, although I'm not very good at it yet. However, there are a huge number of YouTubers who are good at this game and they all have varying degrees of skill at all the different things you can do in Minecraft. I like to watch the builders and designers and the red stone experts, although the red stone people do get me a little confused at times if their project it just a little too complicated for me! And they will always start out by saying it's a "simple build". lol! Yeah, right!