VB stands for VoiceBank. Basically the files that makes your UTAU be able to sing and show in UTAU (sounds.wav, oto.ini, character.txt, etc).
About the other thing... Spanish is not that different of Japanese as the vowels are quite similar.
So you could just add some consonant sounds (like "hard" j, closed f, rolling r, etc) to the normal japanese voicebank.
English is really a problem. I can't speak English very well but I know English has different vowels.
There are wome reclist list in this thread:https://overseasutau.forumotion.net/software-and-plugins-f14/recording-list-download-thread-t527.htm
Or you could just check some dictionaries and see what sounds you need to do the words.
Ah, a reclist is a list of the recording sounds to make a voicebank. The name comes from OREMO as it's a kind of file in that program. But you can just read them to use in audacity or whatever you use to record sounds.