Agreed above comments about how the miners gain after they had finished the mining

Here is a site where I learnt about blockchain and cryptocurrencies from, this is a very detailed and useful site for fundamental knowledge need.
https://blockgeeks.com/guides/
As I remember, there is a post about PoW and PoS, you should explore more about other than these two, there are a few more consensus method, and do comparison about these method. I believe you will also encounter more questions like what is Hard Fork and Soft Fork, how are the different cryptocurrencies working or solve any problems. There are a lot more to work on.

If you still encounter some questions on a particular issue, actually in bitcointalk there are already some posts of similar questions, you may search it, or from reddit there are also some serious discussion forums, but there are much harder

Hope these can help you