Less means "not as much" and is used when talking about things like space, and time. So for example, you could say "Now that I have more stuff, i have LESS open space in my living room". Space is not countable, so you must use 'less'.
Yes, because you cannot touch and count time.
So I would have to use less when talking about time?
Fewer is used when showing that there is less of something from previous times. So another example is, "You have fewer book pages left than me!". Book pages are something that you can physically count, so you use fewer.
so I could say "I have fewer fries than you!" and that would be correct?
Yes! Again, fires are something that you can count!