Is it your first time playing GTA? I mean you can press Q or E + Left Mouse Button to shoot from your vehicle.
Also, if you desire to suggest something, make a post in the suggestion board.
im gonna try to keep cold, i know i can q+e but why cant i shoot forwards or backwards and they can
Do you mean drive-by shooting from a vehicle's passenger seat? if so, I think you press the button 'H' to be able to drive-by shoot from a passenger's seat, Mine's 'Left ALT'. Holding the 'H' button will stop the drive-by mode.
I hope this helps.
Can't use front-facing drive-by on bikesThis is an intentional feature to balance the combat as it is not balanced for a bike to be able to shoot a car they are following with the car having absolutely no defense.
In case if you don't know why you can't front drive-by from your motorcycle/bike.
Source:
https://mikescnr.com/forum/index.php/topic,7223.0.html