I've been playing the Sims 3 for quite some time but with the Origin sale going on right now I decided to take the plunge and finally buy the Sims 4. Thus far I have to say I'm pretty bored with the base game. With the sale going on I was thinking of buying one of the bundle expansions or maybe two expansions (they are sooo cheap). My question is can they be used together like the Sims 3? I mean can I be a doctor and still live in the city and/or join a club. Also do the worlds accommodate each other--I mean having room for work and social lots together? How does it work?
Thanks in advance.

Yeah all the expansions run at the same time and their features are compatible with each other. Work lots no longer exist with the exception of owned businesses and professions (both in the Get To Work expansion). There are loading screens every time you travel from lot to lot.

Sorry just to be clear--If I live in "Get together's" Windenburg, I can still be a doctor with" Get to Work" added even though I don't see a actual hospital or police station in Windenburg in the maps I've seen. I don't have to play the towns separately? Is that right?

Yes you can. For some reason, the Police Station and Hospital aren't in any of the neighborhoods. They're lots that can only be accessed under certain circumstances. So it doesnt matter what neighborhood you're in or what other packs you have. Expansions work exactly how they did in previous games.

Thank you!