Good morning companions

I'm a layman but crypto, I'm learning from you, Bitcoin is actually falling these days. I read several publications here and now several doubts have arisen. If the value of Bitcoin falls by half, will the value of other currencies also fall? Others say that even the Bitcoin rises again to the level of $70k, several currencies have disappeared? If you keep buying, buying will make a loss in the short term and perhaps a profit in the long term? You only make money if you first buy the cheap currency at the beginning of the cycle and wait for the end of the cycle to sell? The rest are left with the crumbs if they don't take a loss.