Wedding music/ ceremony songs

Hi all,
Planning a surprise registry office wedding.
My partner and I don’t have a ‘song’, we have lots of songs that bring back fab memories and remind us of certain moments… but not really wedding appropriate!
I’m a bit clueless and we want a pretty low key and fuss free experience.
I’m in need of some inspiration… What songs/ music are you using for walking down the aisle? First kiss? Signing of the certificate? I’m a bit clueless as to when you have music.