will be a night shoot
im using a alienbee strobe
OK, now we are getting somewhere.
First thing is that the camera should be in Manual mode.
The exposure from the strobe is controlled by the aperture setting and the power setting on the strobe. The shutter speed has no bearing on the flash exposure, just remember to keep it longer than your camera's max sync speed. The shutter speed can be used to control the ambient exposure though.
So if you use a fast shutter speed, 1/200 for example, your ambient (background) is likely going to be very dark. But if you use a long/slow shutter speed, then you can get more ambient exposure.
The aperture & ISO will affect both the ambient and flash exposures.
Lastly, the distance from the light to the subject, will also affect the exposure from the strobe.
A flash meter is the right tool for measuring the flash output, it would tell you what aperture you need to use for the shot. If you don't have a flash meter, then you should be able to get there by guessing & testing.