Step one is probably to try and install Bitcoin core on your PC if you can. It's quite a big download so it might be a hassle but it gets you familiar with how the basic components work. You're right to focus on Bitcoin first because there is lots to learn - focus on learning all the best security practices, especially if you will decide to hold funds outside of an exchange. I would say it is ok to get a basic idea of how mining works, but it won't be super critical to most people as it is difficult to do profitably now. One thing you really need to learn is transaction fees and how to pay the lowest amounts - using different wallet types can literally make the difference between spending $50 to move $500, or spending $5 to move the same amount (look into bech32), this can save you a fortune in the long run. Bitcoin forks will make interesting reading as more of a curiosity than anything else. Personally, I'd stay away from trying to make money trading - you can lose a lot of money, see if you can create any products or services to raise BTC instead.