All three starter options in the Lab (Boneca Ambalabu, Frulli Frulla, and TungTungTung Sahur) are Common rarity with no type advantages over one another, so the matchup system plays no part in your decision. The only thing that matters is the moves each one brings.
Boneca Ambalabu and TungTungTung Sahur are the two picks worth making. Both start with Shield (the strongest defensive move available this early) and Bomb (a reliable offensive option). That combination lets you soak hits and deal damage from your very first fight. Frulli Frulla's move set is weaker, so skip it.
Since the two recommended starters share the same move pool, their performance is essentially identical, and you can pick either one on preference alone. Do not delay wild hunting because you are attached to your starter - Golden Box unlocks matter more than starter sentiment in Catch a Brainrot.