I would keep holding all the coins until the new bullrun starts (maybe it already started). During bullrun any of your coins will grow and if you don't need any coins you will be able to exchange them for ETH or BTC. But in any case, you should learn more about your coins to determine which of them are promising and which ones are not.
I agree with you . Determining a good coin can help you earn profit on your investment. This can be considered the most basic thing in this market and if you have a great knowledge to determine it, it will be good for your portfolio. I think if you choose a bad project in this market, it will be very difficult to make a profit and you will face many difficulties in liquidity.