I'm not sure if I can link mods here but I can list them.
Ani's Fridge Mod- Makes it so you have to go to the store to get groceries. You just can't buy ingredients from fridge
https://www.nraas.net/community/No-Fridge-Shopping
Any and All Recipe Mods- Modthesims has plenty! I love having a variety of foods in my game.
https://modthesims.info/d/574882
Gamefreak130's write thank you notes fixed- This feature broke with a game update, and I loved writing thank you notes
after a wedding, this mod fixes it.
https://modthesims.info/d/620548/write-thank-you-notes-fix.html
ID Catalogue search- LIFESAVER! Sometimes I can't find an item in game, because its buried. This mod adds a search feature like
the sims 4 has. I will never play without this mod again.
https://www.patreon.com/posts/ts3-catalog-mod-82175020
BluegenJutsu's No formalize for proper trait- I love the proper trait, but hated that they kept wearing formal so this fixes that.
Website requires a login to access,
SweetSimmer's Functional Toddler slide- I always need more toddler items! This one is cute.
Zoe's Knitting Mod- Adds knitting skill to the game.
https://modthesims.info/d/659365/knitting-for-ts3-interaction-and-skill.html
Lyralei's Sewing Mod- Adds sewing to the game.
https://modthesims.info/d/643837/ts2-gt-ts3-functional-sewing-table-beta-v2-0-0-please-redownload.html
Job Overhaul Mod- Completely redoes the job system in game.
https://modthesims.info/d/629524/job-overhaul-interviews-and-more-updated-30-may-2021.html
As for Challenges, I am doing my own Medieval Challenge at the moment. Using the custom world of Praaven.