taytaylewlew11 You should always play with the computer plugged in. When it's unplugged, it will throttle performance somewhat to try to extend battery life, which means Sims 3 (and anything else demanding) will run worse and possibly crash. If you don't want your laptop always charging, there are third-party apps you can use to tell it to stop at whatever percentage you prefer.
I would only try disabling wifi if you get another crash with the computer plugged in. It may well help, but it's important to establish what causes crashing and what does not.