How can I crack a veracrypt encrypted partition?
That's exactly what to expect: all weird symbols. On the other hand, if you ever had something like "veracrypt bootloader" in your header, then this was an invalid header that you should not be able to crack.

Unlike LUKS there's no way to validate if a TC/VC header was extracted correctly. You just need to do it 100% correct. If you're unsure, try it with an own disc first (of which you know the password) and then reproduce with the actual target.