The current market situation is bad and all coins are down, so you have to be extra careful if you want to invest and buy at the right time for fear that all coins will go down deeper.
You have to wait for the price to go down again to make a purchase and wait for the market to fall at the last point so you can analyze the coin you want to buy then hold it.
and my advice you should buy 50% in bitcoin and 50% for some Altcoin like Erhereum, Litecoin, and others.