That’s loads more planning than many 
If you’re serious about it, you may want to engage a paid consultant for a session or two get a basic development game plan. The @bubble documentation is mostly technical and doesn’t really cover the bulk of the app-planning work that’s needed. This is really unfortunate, but it is what it is.
The good news is you are absolutely on the right track to plan ahead rather than just building something and having to re-do hours and hours of work to fix a mistake in planning.
Some basics that come to mind.
(Starting at the most upstream)
User stories.
Come up with a few hypothetical users and their full backstories. Flesh them out completely.
“Joanne is a 54 y/o retired business executive. She’s looking to book a conference space for her philanthropy group. She has minimal technical ability but is very interested in the offerings on the website. Her daughter is going to help her book her first appointment”
Who are your users? what are they doing? Will they really need the features you are planning to build? Did you discover new features you should add? understanding this as soon as possible will save you countless hours.
Pages (you’ve done some of this)
Come up with a list of pages you’ll need and what they’re going to do. Mockup drawings starting with low-resolution (i.e. ‘napkin drawings’) and working to mid-res (graph paper) to high-res (in bubble or mockup software). I recommend at least playing around with something like Adobe comp for iPad or Sketch because the speed of which you can practice with UX is significantly faster than bubble.
To SPA or not to SPA?
Do you want a single page application or separate pages? Some combination of the two? Although bubble isn’t purpose-built for SPAs, its certainly doable and a good option thats scalable and and a serious thing to consider that is foundational to your design. You’ll want to read up on this a bit if you don’t know about it.
DB architecture
This about this deeply and do it early. Before you build anything. Your whole app relies on this and you can’t easily rebuild it without making major time-consuming changes to your app.
- Figure out what types you need. Orders, Bookings, Customers, etc.
- Figure out what questions you need answered:
You can start by writing out plain english questions about what questions your db will need to answer. You can go through your page mockups texts and say what would I need to ask to get this info.
-This will help you identify the types as well as the relationships you’ll need. - Database diagrams can be useful too!
- List out every database field you are going to need
- Read up on db questions on the forums.
APIs
Think about what data you’ll need to pull into your app. See if existing plugins will do what you want. Do you need to have any APIs built?