I'm trying to find out how many copies the band PaloAlto's first,
self-titled album sold?

You'd need to find someone in the music industry with access to
SoundScan figures, which can be quite costly otherwise... Members of
the press can get a special rate for sales figures of individual
titles, but other than that, their rates start at $3200 US to track up
to 20 specific titles for a 6 month period.