zEdit had some patches of it’s own, that were quite popular and widely recommended back in the day. There’s a rather incomplete list of patches the patch may include here. If you only used it for merging, the plugins merged should be in the categories still, or in the .esl’s mod description.
As for the ordering it’s all somewhat complicated imo, and also somewhat contentious depending on where you look online. Last I modded Skyrim, I followed the Open World Loot guide, which I found quite useful.
I will also plug a script I put on nexus that generates bashed tags for all plugins you select in xEdit, as some mod authors forget that Bash Tags are a thing :p
It’s honestly nearly impossible to keep up with the essentials after any amount of time away. So many groundbreaking mods come out monthly, that I used to stalk the “Updated” tab just about every day.
There are so many essential and almost mandatory mods for Skyrim, lists get outdated fast. Though Lexy’s LOTD list has an entire section of mostly up to date things. I’d recommend giving it a skim, though it may want you to install more mods.