You need something to use as a ball(actual soccer ball, tennis ball, bunch of rags tied up as a ball, whatever), some players and some space, preferably with some grass.
These are the essentials that every coach and player needs to edify, etch permanently, tattoo and chisel into their brain.
Without these three elements you cannot play the game.
Let's talk about the key elements of places where you can play.
Anywhere. It only need be relatively flat, not on a hill, and preferably not near a cliff. I have played in tennis courts, back yards (I destroyed my parents barn door practicing free kicks), pastures, driveways, streets, parking lots, and all classes of fields, from muddy swamps, to unbelievably green and pleasant. It should be clear of obstructions, although minor ones like large rocks and shrubs help you pat attention to your surroundings and keep your head up. One guy I played with used his parents shrubberies as a "wall" to shoot over and around. After he nearly killed them by consistently hitting it for a couple of months, he became quite good.
Nets. Got a couple of shoes, rocks, jackets? Well put them on the ground and use them. Be prepared to argue that it went in when it didn't and vice versa. Arguing is part of the game.
Balls. Get them anywhere. They are cheap. Even the worst ones will last a month or so. If not use a basketball, volleyball, European handball. Just make sure it has some bounce and will roll a bit.
Players: Anybody who wants to play. From 2 to 200, who cares. Get them on the field. Just pass and move. Shoot and score. Stop and save.
Just play the game.
