if I decide to make it freely available, I'm still unsure whether I will make it open source or use a server.
If you're planning to monetize it then you'll probably need to host it on your own anyway, so I guess you'll have to use a server. You can still make the base code open-source I guess, and add new features that are only available on your customized service. They are not mutually exclusive. There are dozens of open-source software out there that keep being updated and people support the dev through Patreon for example. Not sure how it would work on your project though, since the market is quite niche.May be OP still can go for AWS or other cloud services and fetch the data for open source purposes. They have various options available and plus its always costly when you build up your own server. Hardware server specifically are very rough to manage. You need to have back up servers in a different location than the current location and thus it adds up more cost to the project. Anyways, all of this is only manageable if OP really wants to do this long term and not just for trial purpose as freshman. They will surely need good amount of money to pour into this before perfectly running server can get established.
Also, heartiest congratulation to OP. Do get involved with GitHub community and have all your answers easily found.
