how do bhop?

I doubt an AutoHotKey would work all-around. Only a few maps have some flat areas where the time between jumping and landing is the same.
Go on B-Hop servers with Auto-Hop and hold space to understanding the mouse and key movements. Don't spend to long there, and move on to
using your scrollwheel (keybind in post above).

Most Bhop server have a higher tickrate, which actually does have an impact on your Bhopping. I believe they are mostly 128 tick, if not more,
however Valve's own matchmaking servers are 64 tick. If you play a lot of MM and want to use the Bhopping there, you should practice just as
much on those as you do on 128 tick Bhop servers, if not more. The timing is slightly different, but can be noticeable, furthermore the MM servers
have restrictions on max-speed and whatnot. Upon exceeding max speed, it automatically slows you down. The trick is therefore to maintain
somewhat max-speed, which is not an easy thing to do.