personally use Visual Studio Code (it also handles C#), and have used Atom extensively in the past. All of these are very good, and also free (open source), so try one to see what you like.
Seconded

I use Atom for this game. It’s a bit heavy (slow to load, memory) but seems to work a little better overall on non windows systems. Visual Studio Code I use at work on windows and it’s solid. The “secret” to using either IMHO is:
- load up the plugins you need to color code the text/XML

. It’s not much, but it really helps see everything.
- learn how to open other mods (and your own) as well as the /Data/Config game folder (where all the XML is) as “a project” in these editors. This helps a lot when working with a lot of files.
- learn how to “find something in the file I’m looking at” and “find something in the entire project”. once you start modding this game, you’re going to want to search the games XML A LOT for a word or a number (“where is loot id 546?” Or “I know drinking water gives back a glass jar, is that in the XML somewhere, because I would like to make eating meat give back a bone”.
there’s a lot of other little pitfalls, but making XML mods for this game is relatively easy, just starting out is a bit rough if you’ve never done it before. I would recommend how I started modding (also mentioned above): find some small, simple mods others have made and play them in the game (and learn how to go into god mode in the game, for testing). Then make changes to these mods and see how it all fits together. The forums have a lot of information/help but you will spend more time trying to understand it (because there is so much, covering a lot of areas, and older info from earlier versions of the game) from reading the forums than you will trying to make your own mod and then asking/reading the forums when you have a specific thing that you are trying to do. Just jump in and give it a shot! I have made a lot of mods where I had an idea and .... it failed to work

so I put it aside after I cannot find an answer and try something else (some other mod idea) and hopefully I will learn enough to go back and finish those older mods, or learn what I wanted to do was way too much work/time for me to put in.
good luck! These forums are pretty good with answering questions and helping, as are most people on the forums.
Also: be aware the game is still “in alpha” so every release that comes out may break your mod(s). Usually it’s not a big deal, but try to use it as a learning experience. I have heard that UMA is getting changes. Even if this happens, and you did a lot of UMA work (which I believe snufkins zed mods are a lot of) learning how to repair/retool your mod to work with the new changes can be a great learning opportunity, if not a bit frustrating