I’ve been trying to figure out how to bunny hop in Portal, because I've been running and jumping for pretty much the entire time I’ve had the game. Does anyone know a helpful video or something?

Bunny hop in Portal is very limited, it's kind of circle jumping. Don't use BH acronym for Portal because it's very close to ABH; sourcerunners usually say bhop instead.

Basically you need to maximize the scalar part of the velocity vector that is going to the direction you want to go. In the BHOP in Source, you need to use the part orthogonal to the direction (forward or backward) so left or right directions and maximize them so that you go further forward by looking at an angle. So you need to have forward speed (so press forward); then jump and release all keys. Midair, you will look with a slight angle to the direction you want to go. Then, press the strafe key in the opposite direction. When you land, press jump then swap to the other direction. Example : Forward Jump Look slightly right, press left strafe Jump look slightly left, press right strafe Jump

Continue the sequence

I would add that BHOP is shit in Source Engine, and you should rather learn ABH/AFH/ASH/S-TAP if you are learning a run that isn't Glitchless.