Most of the essentials have been incorporated into the game over the years (party TP display, buff timers, equip sets) so just make sure those first two are enabled in your in-game settings. Anything else is subjective, and if you're only playing for the sake of story completion, you're totally fine playing vanilla.
If you're planning to stick with the game long term, consider checking out Gearswap or Ashitacast, and if you're playing Bard in any serious capacity you'll probably want the modded status icons that colorize song buffs. (Use xiview with xipivot to get just the icons without all the UI mods, and include the modded map dats while you're there.) The skillchains and timers addons are both globally useful I think.
Besides those, there are a lot of nice QoL addons, but personally, I try to keep the amount of extra crap on the screen to a minimum. I don't like the minimap or the FFXIV bars for that reason, but they definitely seem popular.