To find the next project that can go up 100x like Cardano, XRP, SAND, etc of course it is difficult, I prefer to invest in strong coins that have great potential to be the next 100x, and for new projects then I prefer to keep in the short term.
The strong coins are the top 5 and not the rest. Newly launched projects are never going to be as big as Bitcoin or ethereum. These coins can go 100x, no doubt, but truly speaking this is a difficult to make prediction.
There are easier to make decisions, like buying Bitcoins. But few people actually make such easy steps.
Buying and selling are a part of the trading process and selling for a profit is not wrong.