Welcome to IS modding 
If you have questions, feel free to ask. Modding is a bit more complicated and might require discussing code and explaining things with screenshots, so the forum is a good place. I’m also available on Discord but not very reliably anymore in the near future. Also I’m traveling these days, but in general I’m excited that somebody else is picking up modding for the game.
When it comes mods there are 3 levels of programming involvement:
- No scripting at all
- Create a mod class like in the tutorial and do everything in your own code
- Use patching to modify existing parts of the game
First you need to figure out which type of mod you are going to make. It sounds like you are on level 2 or 3. To be honest, what you can do with level 2 is so limited, that you are almost always directly at level 3. What exactly do you have in mind for your mod?
I did all script modding with Visual Studio 2022 Community Edition and it worked really well for me. Not sure if I would use a different setup these days. For the decompiler I recommend ILSpy which is available as an extension for VS2022. You also need to download the Harmony patching library if you want to do level 3 mods. Get it here. You’ll also want to read the documentation there. If it helps then I can upload the source of one of my mods (but earliest would be around 7th October).