Planning An App

So, I'm in the middle of planning an app, and I've started on the Figma design with a view to using Bravo - I've added Bravo tags (hopefully in the right places) but there's some functionality I'm looking to incorporate that I'm not sure how to implement properly because of my inexperience! 🙂

This is my first time using Figma, first time trying to design an app, and my first time looking into APIs, databases, functionality, etc.

I'm jumping in at the deep end, and these  may be really stupid newb questions, so please be gentle with me... 😃

As they're likely to be available through the App Store and Android, I'm unsure as to how to handle the log in element.  What's the usual way of handling that for apps on those stores?  Is it a case of having a log in with several types of log in options?

The app itself will be for people to save and retrieve data about their animals.  So I'd like a few options really.  

No animals - for people wanting to use some of the non-animal features
Add One
Add up to Five 
Add up to Ten
Add Unlimited

But I'm unsure as to how I organise a database for this sort of thing - I've not created one before and there will be a lot of fields for each animal.  When I try to read about setting up a database, my brain starts to dribble out of my ears...

I'd also like to add a 'location' element, where people can place a pin on a map for dog walks and other similar functionality.  Possibly even push notifications surrounding location information.

And finally, a social aspect where people can join a community of people who use the app.

I'm enjoying designing the look and feel of the app, and making some great progress, but I think it's time I populate this with data and features to make sure it's going to work the way I'd like it to.

And I'm hoping all of this sort of thing can be achieved with Bravo, but I've got a lot of learning to do.

I'd love your suggestions and pointers if possible.  🙂

Thanks for reading,

Paul