It has been a while since we’ve had an addons question.
Recommending addons is dicey. Some of it is about personal taste. Some is playstyle requirements.
Some is choosing between addons that do the same thing - for example, I use Threat Plates for nameplates; others might use something like Plater. I use DBM (Deadly Boss Mods) for encounter warnings and timings, where others prefer BigWigs+LittleWigs.
You might take a look at ElvUI. It aspires to provide all your playstyle addon functionality, to the extent that it pretty much takes over your whole UI. Some people love that. I hate it. A lot of people like bag addons that make your bags appear as one; I can’t stand those.
Here is a good presentation of ElvUI
Then there are combat addons for PvP, that have an entirely different focus to PvE, indicating enemy class and cooldowns remaining for example.
The best way to check out addons is on YouTube, where you can see them without investing a lot of time installing, testing, uninstalling.
To get and manage your addons, I use WoWUP from https://wowup.io/ - it’s lighter and cleaner than Curseforge’s own installer.
Here is a pretty good recent presentation of addons
and here is one with a focus on Healing
After you have absorbed that lot, please come back with any further questions, and I hope that I or someone can help,