Mad Max

This should come naturally, but to build the projects, you need to collect project parts. You'll have already been trained for this at Jeet's stronghold, but if you kind of rush through the story, you might end up at Gutgash's Stronghold earlier. There are several types of projects around the stronghold (Food, Water, Ammunition, Fuel, Scrap, etc.), and if you already completed a certain side mission, then you may already have one project completed without realizing it.

To complete another, if you already have 500 scrap collected, you can just add to their scrap stockpile, and that counts. If not, you can click the left stick and hold it to see a list of projects and how many parts are required. Pick a simple one with few parts (but not fuel, since that usually requires clearing camps, which take longer), go up to the silhouette of the project (an orange-ish placeholder for the project) and hold A in order to track the parts needed on your map. Then go collect them, come back to the stronghold and build the project at the same silhouette (it will be bluish now, instead of orange, meaning it's ready to be built). Voila! Achievement unlocked!