multiple categories on one post

i’ve never quite figured out the PHP or whichever code I need so that when one single post contains multiple categories it shows correctly. for example…
post #1 is only a general post so it would say
“categoried as: GENERAL”
post #2 is website related AND general so it would say
“categoried as: WEBSITE & GENERAL”
but everytime I’ve tried anything it comes up looking like
post #1 = “categoried as: GENERAL &”
post #2 = “categoried as: WEBSITE GENERAL &”
help would be appreciated since I’m lost ^-^;;;