Unfortunately there is no Alliance Guild Directory at present, only a Horde one. I recommend joining the Wyrmrest Accord Discord server, as they have a channel dedicated to guild advertisements that would be your best bet at finding an active guild that’s the right fit for you and your character. As helpful as forum directories can be, they can become awfully outdated very quickly.
Alternatively, if you’re interested exclusively in Night Elf guilds, I recommend reaching out to the moderators of the Kaldorei of WrA Discord for a server invitation. They too have a guild advertisement channel for Night Elf-oriented guilds which is kept up to date.