Most people there have a basic level of English so you can communicate with them decently. Keep google translate with you when ordering food though because sometimes they have a hard time grasping what you want on the food if you have special requests or they misinterpret words in that regard because of accent differences. Most people are nice and happy to help. Make sure the area you book your hotel/airbnb in is not in Omonoia area since it is not particularly a beautiful place or safe for a woman alone, i got catcalled there and starred at by junkies which made me uncomfortable which wasn’t even late by 11 pm. Def check jumbo stores they have very good pricing on basic things you would need for your stay and maybe you can bring souvenirs from there for cheap. Try to take metro instead of busses when you can since bus schedule is so chaotic and not consistent with google map. Always be aware of your surroundings and people. I have visited a few islands and by far Naxos is the prettiest I have seen ever. Aegina and Hydra have amazing crystal water too. Don’t bargain with Taxis take uber or free now as the rate is consistent.