Photos sharing

For photos sharing, if your participants have Google accounts, Google photos shared album can be an option: https://guidebooks.google.com/iphone/photos/how-to-create-a-shared-album

Other services, like https://www.kululu.com/ (free test account available) and https://dropevent.com/ could fit your needs.

Some suggestion from https://www.thetravelteam.com/a-complete-list-of-photo-sharing-apps-for-your-next-friendcation/ might fit your needs