If you want to enjoy Civilization 6's battle systems, it'll be best to pick up the Aztecs, Scythia, or the Spartan Greece. Aztecs allow your own territories to have more tile improvements as their Eagle Warriors convert slain units into Builder units. Meanwhile, Scythia's units have bonuses against targeting wounded enemy units. Lastly, the Spartan Greece units generate Culture per enemy unit killed. Waging war in the earlier eras yields fewer Warmonger penalties, so feel free to siege other Civilizations or City States if you need something from them. If you manage to take every Capital or wipe out every leader in the match, your Civilization will attain the laborious and difficult Domination Victory.