Which is a safe coin to invest in the long term?
How long should I hold it?
Is there a risk that I might lose it all?
I am a noob in cryptocurrencies. Help.

I was thinking Litecoin, is it a good idea?
I recommend you to invest in the BTC & ETH. It's a future bright. I believe it will increases in price in the future and it's will give you a huge profit in future.