kaibear0203 Looking at your specs, it's not surprising that Sims 4 doesn't run well on your laptop. I can't tell you whether the limiting factor here is the processor or its graphics chip or the 4 GB RAM, but what I can say is that an external drive would help with none of that. Your internal drive is quite small but isn't close to full, and it's fast enough that a standard external drive wouldn't be an improvement and could be a lot slower.
One thing you can try is increasing the size of your computer's page file, which is somewhat small. The page file is where the processor stores data that would normally be in RAM but doesn't fit, which would almost certainly come into play while it's running Sims 4. Here's how to increase the size (option three):
https://www.elevenforum.com/t/manage-virtual-memory-paging-file-in-windows-11.8618/#Three
Set the minimum to 12288 and the maximum to 16384, and restart your computer. To be clear, this will only help with memory-related issues, and then only maybe; it won't do a thing for performance issues related to teh CPU or GPU. But it's very possible that RAM is the limiting factor at least some of the time.
I would also suggest restarting your computer immediately before you want to play, and not opening any other apps at the same time.