online multiplayer game on 2 separate device

hey guys , i’m sorry for asking this question it may be asked before 100 times .
i’v been searching on youtube and forums entire day .all i found was network projects that i had to play in my unity editor and my .exe build of that project on my own computer.i want a playable scene that can be played from two separate computer or two separate android devices through wi-fi or mobile internet data.
it would be great if some of you guys tell me what exactly should i search to find that kinda multiplayer game tutorial?
my question is that even possible to make a simple online scene in which 2 players from two separate devices can move around ,shoot balls and score some goals?
i only need this project for my university project for demonstration.
can it be possible for free or i have to pay for server account and all those things?
thanks

Hey bty look at the network lobby on the asset store its realy great. it has match making and IP address connection. hope this helped. You can change a lot of things about it for instance the amount of people in game and the amount of people in the lobby