There exist various single addons for different dungeons or trials.
Use the addon search here and search for "helper" or "trial" or "raid" or "dungeon" e.g.
https://www.esoui.com/addons.php

One that is about to help with trials/raids is this addon:
https://www.esoui.com/downloads/info1355-RaidNotifierUpdated.html

But the best is to learn the mechanics of the raids and dungeons by watching explanatory videos, watch the "say" chat for boss/enemy texts and watch the visuals of the enemies, as not all mechanics and enemy behavior can be detected and shown to you via addons (which is good!).

a general one would probably be codes combat alerts

then there are usually specific ones for certain content such as trials (qcells dreadsail reef helper, rockgrove helper, etc)

i dont think theres any particular ones for dungeons though