How to determine range and domain in any graph?

Range is all of your "y" coordinates, and Domain is all of your "x" coordinates.

So for example, if we were to use a linear equation:
y=2x+3

We can infer that 3, the y-intercept, 5, the next number after three, as it is increasing by two, hence the "2x", and 1, the number before x=0 are all range coordinates. So, all odd numbers!

Considering "2x" means "two y for every x", you can infer that range is every single number, as it rises/falls by one every time consistently.

Hope this helps!