You get your first vehicle in Borderlands 4 very early, at the end of the main story mission “Down and Outbound” , which is the third main mission after “Recruitment Drive.”

What happens

  • The mission takes you to the Crimson Resistance/Outbounders side of the story.
  • After you finish the objective and speak with the NPC who hands it over, you unlock the MAV-880 Digirunner.
  • Once unlocked, you can summon it from anywhere on the map.

In practice

So the short answer is: you get vehicles during the early campaign, not right away at the start.

TL;DR

Finish Recruitment Drive , then complete Down and Outbound to get your first ride.