Ripping the assets of an paid game and making them available for free is already in an legal gray area, since it's technically protected by copyright law. Reselling definitely isn't allowed.
(Take this with an grain of salt, since I'm not a lawyer)
Most of the music in Baldi's Basics is an MIDI Format. The file location them is in /Assets/Resources/mididb/. Note, you have to use Windows cause of the Soundfont and you probably need Windows Media Player. But some the MIDIs don't sound right. Like Tutorial_MMP_Corrected, where the main melody is to quiet. IDK why
All the translation key (the text itself) is in the normal compiled game. its in the game directory then "/BALDI_Data/StreamingAssets/Subtitles_En.json". You can change the text and it will work without any mods.
And the font is in the assets under the name "Comic_[something] Atlas.png
I hope this is the right thing you wanted. :)