Start right with crickets, mice, roaches, superworms, quail, etc, whole animal foods only. After all as a baby its the most important time to feed food with a good source of all needed nutrients and calcium.
Bypassany urge to try dogfood, catfood, etc they arent any good for monitors either.
The best food by far mice, quail, crickets roaches, and chicken peeps (when big enough). Feed every day, a growing baby needs a good start, if it gets a good start it will grow faster than you can build cages, also make sure its set up close to correctly as far as caging (ie no screen tops, vent in the sides, good dirt substrate, low wattage lightbulb for a high basking temp on one end and a cool end to retreat to.