Hi there, I know BTC from long time but I never was go in deep in rabbit hole.

Can someone explain me.

How exactly it is working.

Who is hosting BTC?
Who is hosting mining pools?
If you are not using pools, how can you mining directly from the source?
How to find the main source?

If no one is hosting BTC, and you are mining on your machine, you still need a internet to confirm the blockchain it is legit, so why is hosting blockchain?

If BTC transaction fee is going to the miners, how exactly is going to them?
If miners getting their BTC by mining why they are need fee?

Why on Bitcoin's website there no have software you need for mining? But you must to use third-party software?
What exactly the software is calculating during mining?