There are many ways to build a web app, and I recommend making this a web-based app rather than a native desktop app. Web apps are easier to develop, debug, and use, especially if multiple people need access.

Since you have some Python experience, Flask is a good starting point. It's minimal but powerful, and great for a demo or small project. Django is another Python option, it comes with more built-in tools like authentication, database connections, and admin interfaces. It's not much harder than Flask, but slightly heavier. If your goal is to relearn coding and make a working demo, Flask is simpler to start with, but Django also works if you want more structure from the start.

You could use Java, C#, or other languages, but they tend to be more complicated for beginners. They require learning concepts like MVC or object-oriented programming upfront, and setting up the environment can take a lot of time. For your goal Python frameworks are faster to get results.

Since multiple people will use the app and you want to track who does what, you need to think about hosting and scale.

If it's small organization, and a single location, keep it simple. You could host the app and database on a local machine, like a Raspberry Pi, using the local network. Focus on building the app and authentication first. Add a simple backup plan, like syncing the database to a cloud drive. This is cheap, easy to manage, and enough for a small team.

If there are multiple locations or potential future growth, you'll need a server and an online database so everyone can access the app remotely. Both Django and Node.js are good choices here. Django lets you stick with Python, while Node.js (with JavaScript) has many tools for scaling and deployment. Node.js can be easier to scale later, but requires learning JavaScript and frameworks like Express.js or Next.js.

If I were you, I’d start with Flask to build a simple version and make sure it works. Then make a list of requirements: what data needs to be stored, how often new information is added, whether records need to feed into other systems, and the budget for hosting or a local machine.

For the database, MongoDB is flexible and easy to add new fields, but can lead to inconsistent data. SQL databases like MySQL or PostgreSQL are stricter, you have to define the structure up front, but they prevent inconsistencies. Both options work; it just depends on how you want to manage the data. I would start with MongoDB for the demo, and then migrate to SQL after I get all requirements down which can take a while.

In the database, sure. In the forms, yeah. In the authentication/authorization as well. Pretty much in everything. But this is the same for most frameworks/programming languages. With things like Java and C#, you will learn to do a lot of stuff, but then you will realize that you are learning stuff, not actually building the app, since you will first need to learn a ton of stuff just to start actually coding.

It's up to you.