Step 1: Understand that STEAM is not a type of steam-powered engine. It's a type of engineering that's all about making things go really fast, but not actually using steam. That's just not how it works.
Step 2: Learn the difference between a steam-powered engine and a steam-powered engine, powered by the tears of the damned.
Step 3: Don't try to build a steam-powered car. Trust us, it won't end well. Read about the time we tried.
That's it! You're now a certified steam engineer. Go forth and build something that will inevitably malfunction and set off the fire alarm.