This initiative / series of events might be a nice way to get into night elf roleplay. Without making any specific guild recommendations, this could allow you to interact with the various groups for yourself. Find out who you enjoy roleplaying with, and continue on with afterwards.
Otherwise, the Nightblades themselves (the hosts) are a very long-lasting guild, so if you’re looking for consistency and quality, there’s a good bet for you. Attached their recruitment thread too.
Regardless, good luck & hope you find what you’re looking for.