I just finished reading Xenophon's Anabasis and many of the generals and soliders within the army of Ten Thousand are either gay or bisexual, and specifically capture boys who they view extremely beautiful. In one instance one of the generals in the army even tells Seuthes II that if he wanted to kill a beautiful boy, Seuthes II would have to kill him first. So was being gay or having sexual attraction to the same gender viewed in a positive light during ancient Greece? Was homosexuality even a concept back then? Did any of the city states within Greece outlaw it?
As this is such a broad issue, there's always the possibility that someone will have a new contribution for you to look over but in the meantime, the Gender and Sexuality sub-header of the FAQ includes an answer to the question How common was homosexuality (or what we'd now see as homosexuality) in Ancient Greece? by u/cleopatra_philopater which discusses this topic in great detail.
Happy reading!