Beginner Question: How would you approach my idea?

Hi everyone,

let me first introduce myself:
I'm Felix from Berlin, Germany. I basically have close to zero experience in game development but I have a good understanding of programming.
I always had the dream to develop a little game myself and I think now i'ts time to make my dream come true.
I already have a detailed concept of the game I want to develop but I really need some suggestions on some best practices or experiences or even oppinions.

What I want to create can basically be understood as a football/soccer management multiplayer 2D mobile game where you tap through different menus, make your lineups, build your stadium and so on but without any sports gameplay. Results are just based on calculations and RNG ... so nothing spectacular I guess.

But the point that lets me trouble a lot even in conception state is how a typical system environment for these type of games should look like.
From my understanding I need a client/server architecture. Two players meet in a matchup lobby and chose to play against each other. Player A makes all the setups and commits his team for the match. Player B does the same. Both players will now send their data as a snapshot to a server, which will receive both of them and do all the calculation. The server will then send back the result and the client will render the results he gets from the server and present it to Player A and B. Results will be saved on the server.
Thats just a basic concept of this part of the game.

Now to my question:
What is the best way to face this concept?
Are we talking about turn based multiplayer or realtime multiplayer? Or is this even a multiplayer feature from basic understanding?
Are there any assets which will help me get into it?
Should I consider Unity for making a "menu"-only game?

My first guess was that I need to use something like node.js and socket.io for the server and could use a game engine for the client to speed up the process and make it multiplatform.

Please be aware that I would never consider myself as an advanced or experienced game developer. It's just a project for myself to prove whether I can do it or not. I want to make step by step and I know that it's a long road to go. I just want to make sure to start in a good way and therefore I want to collect some ideas and thoughts from you guys, cause you are much more experienced than me.


Thank you for you feedback!
Best regards
Felix