Hello, again

Last time I asked about some defining features of MySQL and got some nice topics to research, today I come to you to solve a problem I've been casually researching over the past week

Note: My programming skill & knowledge is limited to solving Java assignments, creating a few tables is whateverSQL i.e. I have no industry or application-creating context

1. I wrote this section once and it was too long so here's a short version: we are going to be making a thesis project, topics of what apps should be made will be supplied by real doctors, there is a chance these will be used by them so I guess that means "distributing" which brought me to all the legal stuff(I'm doing a presentation about MySQL and want to explain it), hence the question: Can you make an application that connects to a server with MySQL database, does something with the data and displays it or whatever, and then distribute it FOR FREE? Does the licensing stuff only apply when you modified the MySQL's code? I need more of an ELI5 answer than "here's a legal document you won't understand, read it" - I've probably already read it and yet here we are..

2. I learned there are paid versions of MySQL, after reading how it's all free and you can only pay for support if you want to I was taken aback by the list of features increasingly expensive MySQL versions have(like partitioning, NDB engine whatever that is). Don't really have a question under this point, I'm just surprised. Kinda makes me wonder exactly what features are locked behind a paywall(Community Edition vs Standard Edition) but that proved somewhat hard to research with my limited knowledge, mostly the contact with support?