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?
It is a quite good amount to invest, so you need to be extremely careful with that coins that you will choose in purpose of investing. I would strongly recoend you not to put all of the money into 1 coin