So, the main question is that Is it risky to invest in new crypto coins/tokens? or it is good for a very certain time of investment?
There is no certainty of new altcoin from any side. The first time they are listed, they will be more volatile as they deal with the real market interest. Early investors will mostly start selling some (or all) of their holdings, followed by buying at a new investor's exaggerated price expectations.
Based on your desire description, you expect the minimum possible risk. Then why would you even bother considering an altcoin instead of bitcoin?