Great question! Most importantly, it's your special day, so choose music YOU love. If you're looking for music for the ceremony, choose songs that hold a special place in your heart for the aisle songs, departures, signing of the register etc.
For the reception…there are sing along songs and dance songs. There's SO many, so start with the ones you really like and try to keep the playlist roughly themed. You could pick a genre + neighbouring genres to make up most of your playlist e.g pop and rnb, with the occasional disco song. Or a time period e.g. 80s with a few songs from the 90s and 00s.
On the other hand…it's YOUR day, and the reception is ultimately your party. So you could also treat it like you're picking your party playlist. Choose a combination of songs that you know you and your guests are going to want to jump up and dance to! If it's all randomly selected, then that can be your theme for the evening.
Hope that helps! :)
PS If you are planning on hiring live music for any part of your special day, please feel free to get in contact. We can definitely discuss arranging a set list for the day that will suit the atmosphere you'd like to create. We're also more than happy to learn requests for the ceremony part of the day and for the first dance numbers.