Well,,,what Ive read is about 8 fair size crickets,,,going by rule of eyes,,,,or substitute with worms or whatever other tastey treats you are giving him!!!
I would think growing would stop somewhere in the 1 year to 1 and a half years.
My guy is about 5.5 months old and his father was double the size of my guy maybe even a bit bigger,,,,so,,,enjoy the smallness while it lasts!!!
Ciao for now