do a thorough research on the coin you choose, and my advice is that you should choose the top or oldest altcoin that has a good footprint especially in the long term because long term is the best option that will provide good returns. But it all depends on the coin you choose, so it's best to study and understand the risks associated with the coin you choose before committing and using the money you can afford to lose
Obviously even bitcoin goes up and down, but at least it is not going up down as much as the other ones, and it can always recover when it goes down, even if you buy at ATH price, you could DCA your way back into profit, if you bought at 68k, then you could have bought so much more when it was under 20k and you would be in profit today, it all depends on your strategy.