If you created the file in Blender, you would want to use the 3D printing features built into the program. This would check for manifold surfaces (water-tight) and coincidental edges, points and faces, all of which will cause problems in a slicer and 3D printer. If you didn't create the file, you can attempt to contact the creator, but that doesn't always work well.

There are useful facilities for correcting damaged 3D models, although the model you present looks pretty rough. Windows 10 has a free download called 3D Builder which does a surprising job of cleaning up and repairing damaged models. You might consider to give that a shot.

If the model is a free download, consider to provide a link and I'll consider to download it into blender to see if my limited skills can clean up the damage. Alternatively, send it in a direct message and I'll do the same.