I'm basically asking for a link (like ROBLOX wiki) about scripting for KeyDown (I think this is what it's called? I really have little to no knowledge to the mouse and keyboard things)
Here are some examples I'm trying to figure out:
Basically How to even do it
How to make something happen, say you press Q without a tool/hopperbin equipped/selected.
How to do it with a tool/hopperbin
I'm not expecting a script or someone to teach me via answer, just a link so I can get started. I have little to no knowledge of this, so anything helps.

3 comments
A better explanation would be that the KeyDown event works through the mouse itself. Without the use of HopperBins, to get the mouse and access the KeyDown you would use this method.
I think to check what key is pressed, I'd do something like if key:lower() == "q" then.... or something with byte?
key:lower() == "q" works just fine. Keys have byte codes that you could use in place of where the "q" is.