Yeah, doing this in vanilla Bubble is… d… well, not very efficient. You’re going to have to resort to custom code here.
I actually built something similar in vanilla Bubble, but it was so painfully slow that it was unviable as a commercial solution. (That being said, I actually had paid customers of my first Bubble-native version, warts and all.)
I have two paid plugins that help with this as a result: Calendar Grid Pro (a very novel date/date-range picker that actually inspired some of Airbnb’s work in that area – it uses moment.js) and Parallels (a more modern pure data-processing plugin that leverages Luxon to do MOST of the same tricks, but has no visual front-end.).
Since you’re the DIY type, you won’t be interested in the paid plugins (though I’d encourage you to test them out and follow my videos about them), you’ll probably just want to read/watch everything I’ve ever published about dates. Search “@keith dates” to learn more.
In short, you’re going to have to learn to code some stuff. (It’s not that hard, really.)