If we have a plan to be an instant rich person, the best and fastest thing we can do is buy bitcoin, if you have assets such as property, gold or others then I suggest selling and using to buy bitcoin, I have friends who sell houses worth $ 100K to buy bitcoin a few days ago, he has a vision for a long -term hold.
People do think that the only best time to buy Bitcoin is when the price is low, which i noticed from the beginning of cryptocurrency that bitcoin price can only be okay for investment when you have understand the market, because i know that itself is a kind of place where you can invest and still make your Profit, but the best time to invest in Bitcoin is during the time of bearish market and it's when investors buy more of cryptocurrency against the bullish market
There is no difference from what you are telling about. Low and bearish times are the same but other than that, I can't think of any great times to buy a btc. Buying at highs is very risky because people are doing the opposite move which is selling but if you don't mind waiting for a very long time then I think it is permitted because the price can still recover after some time and then move up to another all time high.
Anyone can invest in crypto and it does not matter if you have a great knowledge with it or not because you can still be lucky by hodling it, like what others did before when cryptos are still new. They just made a gamble and made a fortune later on.