have no exactly time when to trade, you have to follow news, events daily and study technical tools RSI, Bollinger bands...to sell and buy to get profit, and one more impotant note you need to know NOW market are uptrend, downtrend or sideway to target profit ( 1%, 5% ...)
It is good for every one to follow the rules of market which is very helpful in getting profit in trading. Crypto market has so many cryptocurrencies which can not give you same results, it is only Bitcoin which is good and best for long term trading and can give you the best profit at once.
Other currencies can make small profit after trying again and again and now it is the right time to buy Bitcoin because the price is affordable after collecting coins wait for the time of a sudden jump of Bitcoin then you can sell it for making huge profit.