Whenever I find myself questioning what my sims shall be up to, I check their personality and the household's community engagement - if any (I have a system where each house is assigned one skill and one career (not necessarily matching). Once I see what their focus should be and who they are, it is often easier to find inspiration for their activities.
When everything feels a bit uninspiring - you and your sims probably will benefit from a vacation! If you don't have packs providing vacation worlds, you can just buy them a tent and go anywhere to live a few days of simple life, or tourist life. Remember to buy/collect souvenirs, and to take some pictures. It's also more fun if you plan their outfits before going, and perhaps add a few basics to their inventories. Won't need Selvadorada to go wild :)