Starting and keeping pacmans on a worm and pinkie diet?...

[Lija]

welcome to the forum, so glad you do your research first!

if you don't want to do crickets, that's all right, they are not that nutritious anyway. you can do dusted as per Carlos recommendations pieces of nightcrawler as a staple when a frog is little with occasional wax worms, hornworms. Mice can be fed only once a month, but a frog can be totally fine without any mice ever. you can get pacman food and use it once in a while too.
my concern however is that you are saying you have a tank that is big enough, you should have a tank that is small enough for a baby