@juliadsi Could you please list the troubleshooting steps you've tried so far, as well as the effects they had, if any? For example, I tried turning down my graphics to their minimum settings, and I still couldn't load a house, or I pulled my game folder out of Documents, letting a new one spawn, and I created a family and played them for a bit, but once I quit and reloaded, I couldn't get into their house anymore. This kind of information helps narrow down the source of your issues, and it keeps us from recommending tactics you've already tried.
Please also list the packs you have installed. Some, like Seasons, require stronger hardware than you have if they're going to run at anything other than the lowest settings.
@juliadsi Try pulling your entire Sims 4 game folder out of Documents\Electronic Arts and onto your desktop (not just pieces, the entire thing). Then launch the game again. Create a sim or two—they don't have to be anything special—and move them into a house. Then try to play them. Does the game still crash?
Also, please list the packs you have installed.
Using CC/Mods is at your own risk, EA are not responsible for making the game compatible with 3rd party content, the creator is.