Well I guess if everyone is middle-aged that makes me over the hill… LOL
To the OP if you do not want to share the file name that’s OK. If you share the file type someone may be able to point you towards a good app for that or tell you that is not a file that needs to be opened.
In the meantime Google is best at finding apps to open and/or convert files. You just need to input the file type extension, what comes after the dot in the file name.