I feel sleepy from drinking alcohol could it be bc im not used to it .. or intolorence ?

Expected: Alcohol can act as a sedative/ tranquilizer in many people and drowsiness is quite common. Another reason NOT TO DRIVE while consuming alcohol. You can develop tolerance over a period of time, but this implies more frequent and higher amounts of imbibing. Best approach is to accept your response as intrinsic to you, and handle by portion control, or choose to avoid.