History price of each crypto will give you answer for that, since Bitcoin created and tradeable on the market the price is very high volatility, the price can be going up 10 to 20 times in afew month and then going down to 80% to 90%, so if you like to start hold Bitcoin or others crypto you have to start when the price already going down to 80% to 90% and then hold it until reach 10 or 20 times.
Talking about supports, resistance and then price action, I guess they are like the main things that apply to every form of trading when it comes to knowing when you should be buying and when you should be selling. Getting in and out of the market requires strategy and as long as you do not have one, then you are simply gambling.
Now, one thing with strategy is that, there are so many strategies and a strategy used by A may not be a strategy used by B, but what is important is to find your own that suits you best and stick with it, and that is the only way you will even be able to have an idea where to sell or buy or set stop loss as the case would be.
In my opinion this is the best time to in because the prices of almost every coin are quite reasonable for new investors. They can make big profits in the future if they hold their coins for some more time. The bearish situation is gradually coming to an end and good days will start soon. dont be panic about the current bearish situation of the market and dont get out of the market.