Hello & Welcome to the forums!!
You do indeed have a C. cranwelli and it is the most common Pacman Frog in the hobby, most care sheets refer to them.
At that size, we usually offer food daily and the diet is primarily earthworms/nightcrawlers. At this size, you need to cut appropriate sized bits off of the worms for the frog. Poop is normally every 2 to 3 days for ours depending on how much & how often they eat. The earthworms can also act as a mild laxative and may help get him to move any pebbles left inside if any.
Best of luck!!