I am new to the Sims 4 but I did change some things using S3PE when i played the sims 3. But I have run into a snag of sorts... well a few actually!!!

First, I am looking for the skills which are in my game right now with all the DLCs I have. Where or what file do I need to open to find things like skills and/or traits?
Second, Where or what file would I open to find the Move In option?
Third, Is it possible to create packages using S4PE like I did with S3PE and only place the xml changes in it?

Thank You for replying to this message. Please keep it simple for me to understand. I am not computer friendly and have 0 technical knowledge so if you answer with a lot of multiple syllable words, I am gonna ask dumb questions.... I just want to make a couple mods which first of all allow someone to ask someone else to Move In, much like the mod create by SolaceInSound for the Sims 3 located here: Solace In Sound's Move In Mod (Sims 3)
I also would like to see what skills can be used within the game with the DLCs added.

I know about the stats.set_skill_level cheat which you can use to level skills. The ones I knew about were:

AdultMajor_Bartending
AdultMajor_Charisma
AdultMajor_Comedy
AdultMajor_Fishing
AdultMajor_Gardening
AdultMajor_GourmetCooking
AdultMajor_Guitar
AdultMajor_Handiness
AdultMajor_HomestyleCooking
AdultMajor_Logic
AdultMajor_Mischief
AdultMajor_Painting
AdultMajor_Piano
AdultMajor_Programming
AdultMajor_Reaping
AdultMajor_RocketScience
AdultMajor_VideoGaming
AdultMajor_Violin
AdultMajor_Writing
Skill_Fitness
Major_Herbalism

But I just found these 2 as well:
AdultMajor_Baking
AdultMajor_Photography

And I would like to know what other skills can be leveled in the game....

Thanks

Hmm 37 views and no replies. Doesn't anyone know what file holds things like the Move In Interaction or skills? Or is it so secret that no one wants to say just so that no one else can create items or things in the game.....

This is XML tuning. You should read the Maxis CC documentation (link see sticky) and the walkthrough in Tutorials (Coding category). See also the links in the sticky on where to get the up to date tuning files, and the XMLExtractor thread in Tools. Yes once you have your XML files done you can use s4pe to plunk them into a package.