Here's the relevant text:
When no bush of the field was yet in the land and no small plant of the field had yet sprung up—for the LORD God had not caused it to rain on the land, and there was no man to work the ground, and a mist was going up from the land and was watering the whole face of the ground—then the LORD God formed the man of dust from the ground and breathed into his nostrils the breath of life, and the man became a living creature. And the LORD God planted a garden in Eden, in the east, and there he put the man whom he had formed.—Genesis 2:5-8 (ESV)
- God created Adam fully formed or
- God created Adam as an infant and placed him a garden where he was able to live safely.
In both cases, it is God who made sure that Adam lived.
A subsequent text suggests that option #1 is correct:
The LORD God took the man and put him in the garden of Eden to work it and keep it. And the LORD God commanded the man, saying, “You may surely eat of every tree of the garden, but of the tree of the knowledge of good and evil you shall not eat, for in the day that you eat of it you shall surely die.”—Genesis 2:15-17 (ESV)
Otherwise, how could God expect the man to work and keep the garden, and how could he understand God's commands?