Yoncakoy is a small village of Selcuk and second closest beach around Selcuk.
It would take 15 minutes by local buses (Dolmus).
You’ll be there in 10 minutes, minibus coasts about 3-4 Liras.
You can go by Kusadasi dolmuses and you would be there in half hour.
Ladies Beach is on the south side of Kusadasi where most of the locals and tourists go. It has a nice beach and a clean sea.