In these situations most Newbies become prey of FOMO and lose most of their capital. They think it has Hit an ATH and will go for a Pullback and they Short. But it continues to Rise higher.
You are doing the first steps wrong. When bitcoin reaches all time high, you would not short it. Once an asset is in ATH, it means that there is buying momentum behind it and it may continue to rise higher. Those who would short it blindly are bound to lose their capital. You should only short when you see a clear change in the structure in higher time frames. When Bitcoin makes a lower high and confirms it, only then are there probabilities that shorting would be profitable.
To be honest with you, newbies shouldn't be doing anything and should stay away from the market. They should focus on learning and then come to the market. The market isn't going anywhere and even in a bear market, the good trader makes money so it's all about patience and learning.