How old do you have to be work at Target?

Minimum age is actually 16.

Target sets the minimum hiring age for store associates at 16 years old.

16 for all positions except for distribution centers, team leads, work involving powered machinery (usually in the back), and if the store has it, bakery/deli/meat sections. You must be at least 18 to be considered for those positions

You have to be 18 in order to be a cachier at Target.