There are two ways to find a 100x coin these days.

First one is presales. You need to find a good project and buy their coin/token for very cheap prices. This is not too easy because most good projects have very low amount of presale and they whitelist addresses. It has too much procedure and there is no guarantee.
Second is new defi swaps. Don't forget it's high risk high reward. Personally I won't touch them with a bag of money. Always do your own research. You also need some luck.