Quote from: Mankov on April 13, 2018, 05:55:38 PM

Hello,
I bought some bitcoin on Cobinhood. Can I send them now to the desktop wallet of bitcoin.org, and leave it there for 5 years or longer, without caring about it in this timeframe

For sure, but you will need to get out your coins from Cobinhood first

To ensure your coin security, I'd be best to keep your coins in a wallet where you control your private key.
Since you are planning for a long term holding I suggest to take either Paper based wallet or Hardware wallet, your private key are now in your hands.

Quote from: Mankov on April 13, 2018, 05:55:38 PM

What happens when Litghting-Network or a fork is coming, do we have to update something?

Lightning Network are a soft fork, when a soft fork happens you only need to udpate your wallet in order to use those new features.