Hey everyone! Does anyone know much about marketing retreats or where good places are to list them?

Question

I'm organising my first ever art retreat and I would love to try and fill the rooms but i'm not sure where or how to advertise it! Maybe in over my head a little bit but fail first right? :P We've sold 3 rooms so far (yippe) so just another 3 to go.

If anyone has experience in weekend events or maybe advertising in general any advice would be very much appreciated!

Here's the link to the event in case you need more context.
https://www.artistand.co.uk/artretreat

Thanks in advance :)