Here is how you go zero to hero in Diablo 4.
One of the most consistent ways you gain XP is by killing enemies.
When starting out, the first thing you’ll likely want to do is focus on finishing the campaign.
Raising your Renown involves completing side quests, finding Altars of Lilith, beating dungeons, and clearing strongholds.
Note that you better be level 28 to reach the Season Blessings system however.