Is a 15-year-old person's enjoyment of a friend (without sexual activity or undressing) considered sodomy or a major sin, and does it affect his ability to marry and form a Muslim family?

The act mentioned, even if it is not sodomy that necessitates a ḥadd punishment, is a prelude to it and is prohibited among grave sins. Marriage is the Sunnah of the Messengers and the instruction of the Prophet, peace and blessings be upon him, and it is a path to tranquility. Sincere repentance transforms evil deeds into good ones, and Allah forgives all sins. Whoever repents and does righteous deeds, Allah will transform his evil deeds into good ones. Drawing closer to Allah brings acceptance and response from Him, and righteous deeds grant believers a good life.