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 would be wise to split into different coins such a big amount of money and most of them for stable-trusted coins, like ETH, BTC and others. Also, you can invest into starting projects which could rise up in price.