Playing in the Zombies mode is the easiest method to level up quickly in COD Vanguard. Every XP you acquire will be transmitted to the Multiplayer mode as well. Longer Zombies battles offer you a better chance of gaining XP. Furthermore, accomplish any and all Missions found in the primary menu settings challenges area. This is the thing you need to do if you like to level up fast. Also, if you want challenging games, try these detective games.