@macybeth12 Technically this is not the forum zone for the sims 4 but for talk about project Renè, but:
1)if you have mods, try to start game without it, if the game start and work, the problem is one of the mod.
2)on the document folder (the path is yourpc or thispc ---> documents---> electronic arts---> the sims 4 delete the cachestr folder, the onlinethumbnailfolder, avatarcache.pakage file, clientDB.package file, localthumbcachefile.package file (for my problem most of the time deleting this items resolve everything)
3)unistall and reinstall the game
4)how old is your hardware? maybe your pc simple are too old, or the hdd/ssd are in bad condition and simply the game doesn't work properly (is hard to say, because with an hardware problem you have problem with everything on your pc, but is a possibility).