Challenges to do

I would suggest the exact same things. The Apocalypse challenge is super fun!

"the only packs I currently own is Seasons and Cottage living...i also got my first pet stuff" Um...what? You need the Dogs and Cats expansion for My First Pets stuff. That's the entire reason it is controversial (DLC for DLC).

In any event, a suggestion is a super sim challenge where you must complete every single aspiration to gain every single earnable trait.

I am the same, I never cared for young families in Sims, and the idea of a 100 baby challenge, You Couldn't Pay Me to Do It! lol

I love simple living challenge, and collecting myself. Though I have more packs, and use some of those packs to increase the challenge. Generally the same idea still can be applied to an extent. Like a Nature Lover collecting all fish, frogs, plants. etc. Here is my personal challenges I have lined up for myself, many parts can just be skipped if, you do not have the pack, many concepts can still be done (like instead of relying on Natural Living Skill, rely on Simple Living).

I love the 100 Chicken Challenge, I should definitely start it over again.

The 100 Baby Challenge is always relevant, in my humble opinion. It took me months to complete it a few years ago (alas, with a full-time job and family).

Here's just a silly challenge I thought of way back, but still has not tried:

Create 4 households (minimum a married couple, but you can set the rules yourself). Each household is based on one color like red, green, blue and yellow. This is reflected in house decor, gaerden plants, genetics and CAS outfits and more.  The signature color won't need to be a 100% thing, but shoukld easily be spotted - you decide the level.  Like the blue household can be aliens with blue skin, but they don't need to have blue skin if say eyes are blue and outfits include something blue. Might be more fun if you go all the way, but maybe you prefer some realism, too. The color shall affect their visuals, but also names/careers/traits and all their choices. It means, when there is a color hint, you will choose it, being a word resambling the color ("read" gives "red" etc), the co,lor of the career or trait icon, or just anything. In many cases you must choose, i.e,. the "jealous" trait might appeal to both the yellow household and the green ("green from envy"). You can stretch it as far as you want. The household members in he blue family will obviously like to listen to blues.

The challenge might be a bit fun when creating all those details, but then you arew supposed to play the 4 households on rotation, make them build relations, and each main hair shall find a spouse in one of the other 3 houses. When children get born, you will hopefully see color sheme blend, and so must your  options.

I can 't guarantee the fun level, but it could at least keep you busy for a while :)