Need Answers, please help

Dear AppGyver community.

Our company is a startup and we are growing.
Our main business is custom handmade carbon fiber laptops and we are searching for a No-code / low-code platform to start going away from the usual excel.

We need an application so the users could check their order process.

So while we do understand the platform how it works and we checked the documentation, we do have a few questions, we hope you as a community of app developers will tell us.

Questions 1: User view data only.
Where can we get samples on how to do this, so that each user only sees hi’s data or if we have a company a stream of users could see the same data.

Question 2: Data connection
So it seems that most of you use airtable or similar products to store data.
We might need a real database for future needs (porhaps Altibase) or at least a hosting from LiNode (mySQL). Is there an example how to connect to external databases outside the API connection methed listed here:

Is there an ETL method. Has anyone used those methods for their app data storage?

Question 3: Application integration.
From the tuturials and youtube videos we havent seen an example how to integrade the application in a webpage or to send it to android or ios marketplace.

Lookign forward to hearing from you as i think the platform itself is offering more than bubble is currently.

Kind regards:
Matej