Will combining scripts improve performance?

Right now, I have a lot of scripts in my game and I’m wondering if moving all the code from similar scripts into one longer script would improve or harm performance.

Short answer: Yes, but not in a single script. There is no need to combine everything in one big script, but having a lot of small ones harms memory. This is why writing frameworks is useful. Keep in mind that all of this is really, really insignificant.