What to choose to create a messenger?

Question

Cross-platform

Advise with what technologies it is better to create a cross-platform messenger? I originally thought to use nod.js react.js is the server side and android studio to create an android application, and interact with the server side using the retrofit library. Then I looked and came up with the idea to create a server part in python django. Or is it better to use nod.js, react.js and react native? There are a lot of technologies and I don’t know where to stop. I'm new to programming, so if someone finds my question stupid or not original, please forgive me. There is a desire to learn, but where to start, a little familiar with android studio, html, css. After watching a couple of lessons on python django, I realized that I perceive information more easily than nod.js. But on nod.js there are examples of the implementation of messengera in python, I did not look for it.

Answer 1

If the goal is training, then you can take any stack you like. It will never go on sale anyway. Did the python go well? So write on it.
In general, there is a server for creating a chat in any popular language.

Answer 2

I do not advise you to write your messenger if you have no experience. A full-fledged messenger is 1000 times more complicated than a simple chat. Because the messenger is not so much about the code as about the architecture. The messenger must be scalable, fault-tolerant, with a cache, queues, a balancer, and so on. Write your chat on nodejs, there are a million lessons on youtube. Do not try to jump through 10 steps at once, go gradually.

Answer 3

in which direction to move what to study to create a cross-platform application?

What for? If you have a problem with just writing a messenger, why are you making it difficult for yourself?
The messenger backend can run on a specific OS, and for cross-platform, different clients simply write on different platforms. There is absolutely no need to suffer and write ONE client for all platforms at once, especially since this is not impossible, but it will be just three different clients in one set of sources, it will be inconvenient to support.
Therefore, do not bother with cross-platform. Just implement a convenient and reliable API for the backend, to which you can add as many clients as you like.