You can trad eon Cryptopia, there isn't a problem there but just make sure you have 2fa enabled as I got hacked there once because I didn't enable 2fa on the site as you might get hacked. Otherwise you can always check out COINMAKRETCAP in the markets section if any new exchanges get listed for ETN.
At the moment I also only see Cryptopia as the exchange listing it. Am curious as to why there ar eno more exchanges for this coin..
https://coinmarketcap.com/currencies/electroneum/#markets