I downloaded some polish subtitles to a movie for my friend’s dad, and some of the characters are just numbers and jumbled looking characters.
I was wondering what I would have to do to get these characters to show correctly.
It is unclear what file format you used to hold the text and which application is used to display the content of that file.
As a general rule, you must ensure that the character-encoding of the text matches the encoding the program expects and also that the font used supports all characters needed.
If you say that only some of the characters look weird (those with some kind diacritics, I assume: ĄĆĘŁŃÓŚŹŻąćęłńóśźż) it is most likely that one of the two parties uses UFT-8 and the other a specific code page such as ISO8859-2 or Windows-1250.
If there were a problem with the font, the most likely effect would be that placeholders (empty squares) are displayed, and I understand that this is not th ecase here.
(More could be said if you gave specific examples of a case of expected and displayed text)