First, here's a link to a free download of your camera's manual
in case you've lost yours.
On page 16 of the manual, it states that in addition to using DX film of ISO 100 to ISO 400:
1) Color negative film is recommended.
2) Non-DX film cannot be used - but then says if it is used, set the film to ISO 100.
3) ISO 400 film is recommended.
Page 25 and forward detail exposure Modes. This should be your next area of interest in the manual. If you are unable to to solve the problem at this point, there may be an issue with the aperture of the lens being stuck open - or the shutter remaining open for too long. Either way, it will probably need to be serviced professionally to get it working again. You might consider replacing this camera as repair costs may exceed the value of the camera.
I hope this helps and good luck! Please rate my reply - thank you.