Yes, if you want to trade, you can often take advantage of the decline. For example, during the decline, you bought Bitcoin at a low price and when the price of Bitcoin increases, you can sell it. If you want to become a trader, you have to learn a lot, which may take you about 2 to 3 years to learn. There is a lot of risk in trading. Very few people have been successful in trading, and the risk of losing your money in trading is very high.
Price can bounce or recover after a fall but it can fall deeper and this makes trading is very dangerous for traders. People can lose money by buy high, sell low with FOMO but they can also lose money by buying in dips and panic sell in deeper falls.
Traders need not only money but some others like knowledge, experience, discipline and very strong mentality to make sure they know what they are doing in the market, and how they control their emotion, decisions for entries and exits, buying and selling. They must prepare their finance very well, and make sure they don't have pressure of always being active in trading for earning money in order to use it for spendings in life.