The sims 4 digital deluxe - own content

If you don't have a mods folder, you can create one. 

you also need a file in there called Resource.cfg

you can create it yourself using notepad if the game isn't generating it for you.

copy/paste this into notepad:

Priority 500
PackedFile *.package
PackedFile */*.package
PackedFile */*/*.package
PackedFile */*/*/*.package
PackedFile */*/*/*/*.package
PackedFile */*/*/*/*/*.package

then bring up the save dialogue. in there select 'all files' from the 'save as type' drop menu and type Resource.cfg into the filename box, then click save.

put that file into your Mods folder.

also, make sure mods/cc is enabled in the game options (Game Options >> Other >> tick the box next to Enable Custom Content and Mods)