A very common mistake owners of such cameras make when loading a roll of film is pulling too much film out of the camera. Most of the time there's an indicator (e.g. red line or dot) showing you where the end of the film leader needs to be. Often users will place the film beyond this point in an attempt to ensure that the film is properly loaded. This is not the case as placing the film beyond the red dot/line will prevent the camera from properly loading the film.

If your camera doesn't have this red dot/line, which should be just the opposite side of the take-up spool, then extend the film to no further than the far end of the take-up spool, or to the end of inside of the opening. If this still does not fix the problem, then the camera is broken and you should look to buy a replacement as any repairs would be many, many times more costly than the value of the camera itself.