@sativsim I'm glad to hear it worked, and don't worry about the late reply. For mods and any custom content that comes in .package form, here's how to install:
https://modthesims.info/wiki.php?title=Game_Help:Installing_Sims_3_Package_Files/Setup_and_Files
For cc that comes in .Sims3Pack form, you just put it in Documents > Electronic Arts > The Sims 3 > Downloads and install it through the launcher's Downloads tab. However, I'd suggest testing out any .Sims3Pack cc in a clean user folder before adding it to your main one. This type can come with hidden files you don't want and that can bork your saves, and getting rid of the worst offenders can be a whole process.
To test the content, move your existing Sims 3 folder out of Documents > Electronic Arts (or just rename it) and open the launcher to spawn a clean folder. Then install the .Sims3Packs into that folder, one at a time, and look through the launcher's Installed Content tab for any cc you didn't intend to install. If the downloads are clean, test the items in-game too. (You can test a bunch at once; just make sure to try every item.) If everything works as intended, you can trash the new Sims 3 folder, restore the old one, and install the cc into that folder.
It's also possible to get bad cc in .package form, but the nice thing is, all you need to do is remove the .package file and you're done. So if you have a choice between the two types of files, always choose the .package rather than the .Sims3Pack. Most cc works fine in either form; the only exceptions are worlds and patterns.