The parameters are the variables used to receive and refer to the arguments.
The arguments are the values that are given to the function.
The list of parameters says how many arguments a function expects. A function that expects two arguments should therefore have two parameters.
When using a function that has two parameters, one should supply two arguments.
What separates arguments in a function call? No guessing. If you don't already know it, then that's something to google or refer back to earlier material if you recall it having been explained already and where it was explained. If you guess then you're going to be making some change that you don't really know if it has the desired effect or not. Perhaps it's got a similar effect, but isn't the same, and then you'll have something even more difficult to debug later and you don't understand what you wrote because you were guessing, so you can't reason about it and debugging gets really difficult.
If you only ever add things that you know what they do, then you understand each thing that's happening, you can reason about it. Stick with the things you know and expand your vocabulary so that you can use more things