Hi there. TS3 mods, the package files themselves, do not belong in Mods\Overrides unless a developer has specifically instructed players to put them there. It's pretty rare, I have hundreds to thousands of package files and a total of 2 in Overrides. Most of the time they belong in Mods\Packages. Overrides is for when one mod intentionally uses the resources of another mod and the order in which they load must be precise rather than random.
This is what your setup should look like exactly, with some differences around the edges for different operating systems. The downloadable Framework from this page includes Resource.cfg (not .chf) already and comes with two small sample mods in the correct place for testing, NoIntroMovie and NoBuildSparkles. After testing successfully, you may keep or discard the sample mods as you wish.
https://modthesims.info/wiki.php?title=Game_Help:Installing_Sims_3_Package_Files/Setup_and_Files
It doesn't matter how Windows (or the macOS) is set to auto-open .package files. The format is used by many different programs/games but they aren't supposed to be opened in the first place unless one is trying to edit them using a package file editor like S3PE. The game will read and put them to use (or fail to do so) just the same no matter what the icon or auto-open preference looks like.
Edit: I really must learn how to type faster, your second post wasn't there when I started. But I'll leave my response anyway in case it also helps others.
The instructions for putting the Mods Framework in Programs would be from before Patch 1.12 that was released alongside of Ambitions back in 2010. Things changed at that point. :)