Re: I downloaded the bitcoin core wallet, what now?

-snip-
So bitcoin could go down if no one host the nodes, if this happens, can someone just download the node and host it on his computer? Or a computer can't handle that?

If in a scenario, no one host a node, you would not be able to get the data of the new blocks from your peers. If you are the only person on earth to have a node, with no latest blockchain data, any data after your last Bitcoin block would be forgotten. Of course, you can mine the blocks and continue the blockchain but it is not plausible with the high difficulty.

So once the blockchain goes down no one will be able to recover it?
If I run the bitcoin core wallet it says 6 peers, so only 6 people host the blockchain at that moment?

Unless they run a node again or upload the latest blockchain elsewhere.

No. There are approximately more than 5047 Bitcoin nodes that has 8333 port opened. A Bitcoin node with default settings only allow 8 outgoing connection unless you open port 8333 which will enable incoming connections.

edit: oops I meant the other way round. changed.