As someone who has been in this since November, I'm sorry to say that the right time to buy was like two years ago. Unfortunately.
the history can still repeat itself with help of volatility, therfor all you need to do for now is wait. besides , the price of cryptos right now had also been droped a major percentage ever since we begin the year 2018 . so i guess buying a crypto these days are still a good idea because their values are still cheaper when compared to their value least year .
i do also believe that there isnt a right time or right date to buy a crypto because the valaue can alaways fluctuate or change from time to time.
I mean sure someone can get lucky, buy the right coin. But Bitcoin was like a thousand dollars a year ago, 600 two years ago. Right now it's considered so low at 6,000. But not only that, compared to two years ago virtually all coins grew. I just find it hard to imagine that we will have such growth again.