Using the Attack action, you can make a special melee attack to shove a creature, either to knock it prone or push it away from you. If you’re able to make multiple attacks with the Attack action, this attack replaces one of them.
You only need the subclass (or the feat that gives you maneuvers) if you want to do it as part of your weapon attack.
Not the fact that you can’t push and trip people without taking an entire ass subclass?
You can always take the shove action. PHB 195.
You only need the subclass (or the feat that gives you maneuvers) if you want to do it as part of your weapon attack.