Step 3: Getting a home.
So go out to your local garden center/borrow from that understanding human in step 1, etc. Just get a pot about 4 times bigger than his root ball. Don't put him in the ground. He might survive, but the shock for the young tree of being transplanted and having to fight off all the inherent dangers of being in the wild may be too much.
Also get some more soil, preferably planting or potting soil. Miracle Grow works great for my needs.
Finally, a little fertilizer cant hurt. Make sure you get the right type, just read what its for. you will probably want something that says 'sapling", "baby plant", "Potting", etc. However, something labeled "flowering" or 'flowers" is common but not what you want.
First, fill the pot about 3/4 of the way up with some of the soil. Using your hand, dig a small hole in the soil and place the tree right way up in the pot. Then continue filling the pot until the soil reaches the bottom of the "trunk". Now fertilize with a light sprinkle and water profusely.