Help with code || Beginner

Hi. I’m quite new at programming (not in general, because I was taught a little bit of Delphi like 5 years ago at school) and really new at programming in Kotlin. My main goal is to learn how to develop mobile, desktop and maybe web apps, but since I don’t have a good enough PC to use Android Studio at the moment, I’m learning to do different things in Kotlin.

So, I’d like to ask if you could check the code that I wrote (it’s a pretty basic program. I struggle to get ideas for projects and this was one of the few that I came up with. I think that I would make it a proper app in the future) and point me any style errors, confusing variable names, lack of good flow, maybe hint me about a paradigm that works better for this kind of things, etc. I ask you for any criticism that you have according to my code, so that I can work to improve myself and take another little step into he Intermediate Programming Universe.

Thank you so much for your help in advance!

Here’s the code: https://gist.github.com/radhalvy/01aea76a390ffe3efffc5f4e3edb5288