One of the super awesome qualities of the game is that there's so many features. Even to this day, after playing over four years, I still come across new things. I'd recommend watching tutorials and survival let's plays on YouTube. A popular one you might enjoy is HermitCraft.
My advice: be super cautious. My first days in the game ended gravely when I lacked caution and took risks I shouldn't have. So don't go wandering out at night until you have decent gear and you're able to combat monsters well. Always carry a good supply of torches, blocks and food when caving too and a bucket of water doesn't hurt for scaling ravines and navigating lava.
Check out the Minecraft wiki for an in-depth run-down of everything you need to know to start out. Have fun.