first of all go to the announcement topics and check where you can sell them. there is always a link there. and also there are sometimes people there selling and buying coins and tokens in each announcement topic underprice if there is no exchanges available.
other than that you can go to
https://coinmarketcap.com/ search the name of your token and check the market tab to see the list of exchanges having the token you want to sell.
Good advice above, i find binance the easiest and feels the most secure due to being the biggest.
It really depends on the coin and where its listed so check on CMC but kucoin i find list many of the alts i trade.