You can get a vehicle in Death Stranding 2 by progressing normally through the campaign. Upon completing the main objective in the Former Geophysics Research Lab in Mexico, you’ll be able to fabricate a Tri-Cruiser. Note that vehicles can only be fabricated in large facilities with a garage, as well as the DHV Magellan mobile base:

• The Tri-Cruiser costs 220x metals, 160x ceramics, and 10x chemicals to fabricate.
• Later, you can add armor plating, which costs 100x resins and 130x metals.

Several hours later, after completing Order 12, you should gain access to the West Fort Knot facility. Eventually, you’ll have the means to fabricate the Pickup Off-Roader, too:

• This heavy-duty truck can carry tons of cargo, though it’s significantly slower compared to the Tri-Cruiser.
• The Pickup Off-Roader costs 320x metals, 230x ceramics, and 20x chemicals to fabricate.