There are not more than 400 to 500 exchanges that are legit, out of them, the better ones will be better to be followed, if you check coingecko, you will be able to see the lists of exchanges according to their trading volume, the best ones are on the top of the list, you can research if the top exchanges have coins or tokens, like the binance which have BNB, exchanges like huobi also have its own coin and some like that. But exchanges with low traing volume, better not to go for their coins or tokens.