Some spells and abilities that create Food tokens may require targets. If each target chosen is an illegal target as that spell or ability tries to resolve, it won't resolve. You won't create any Food tokens.

If an effect refers to a Food, it means any Food artifact, not just a Food artifact token. For example, you can sacrifice Pizza Face (a Legendary Artifact Creature — Food Mutant) to activate Maraleaf Rider's ability (an ability with "Sacrifice a Food" in its cost). You can't sacrifice a Food to pay multiple costs. For example, you can't sacrifice a Food token to activate its own ability and also to activate Maraleaf Rider's ability.

You don't choose a second target for Dimension X Pizzasaur's first ability at the time it triggers. Rather, a second "reflexive" ability triggers when you put two +1/+1 counters on the target creature this way. You choose a target for that ability as it goes on the stack. Each player may respond to this triggered ability as normal.

Whatever you do, don't eat the cards. (Also, don't make the pizzas pictured on the cards. You don't have the digestive system of a Ninja Turtle.)

Food is an artifact type. Even though it appears on some creatures, it's never a creature type.