OUTRIDERS

How fast you level while playing will depend on if you decide to do the side quests alongside the story or after you completed the main questline. The storyline and side quests will get you pretty close the Level 30, though if you had to replay anything, there's a chance it'll get you the full 30 need for the trophy. You'll need to complete Expeditions after you complete the story for Hitting the Jackpot  so if you don't reach 30 through the main/side quests, you'll definitely get it while going for that trophy. 

Your World Tier will have an effect on your leveling speed as well since the higher tier you're playing on, the more, stronger enemies you'll be going up against. Don't force a higher tier on yourself so you're struggling. Just play at the one you're most comfortable on. Even if you stick to Tier 1 the entire time, you'll reach Level 30 by the time you're done with the Expeditions and your class Accolades.