I'm making an app that helps manage some rental units. Ideally, I would be able to input the information of a particular tenant, their payments, the relevant rental unit, etc. Then, the original data and some derived data would be inserted into the necessary tables. I'm watching/learning the SQL course by Data with Baraa (just finished JOIN), but I'm not sure I'm following the right direction. From what I'm seeing, SQL would be excellent later, for the management process, like having pre-written queries that you can use to filter upcoming bills or late payments but not at the start. Asking ChatGPT, it seems to me that SQL is not like Excel and tables and cells in SQL can be automated. Am I getting this wrong? Should I finish Baraa's course? How do I get the data into the tables? Should I be studying something different that is essential to the project?

Additional context: I'm a complete beginner in coding. Before giving up on the project a few months ago, I was able to somewhat successfully run the app with command prompts in Python: input the data and insert it. I* even made auto bill generation and late payment notifications (this was quite clunky, though). But this was thanks to bicoding using ChatGPT, whose code, even though I understand, is completely incompatible with making a GUI app and I had no idea how to fix it. That was a deep rabbit hole and it was absolutely excruciating. I would really prefer not to experience that again. I would really appreciate any guidance or feedback on my approach to the project. Thank you for reading this.

Link for the diagram of the database: https://postimg.cc/zyvhFsrF