Translation:See you later
The suffix -na denotes a "reciprocated" action. In this case, kuona (to see) becomes kuonana (to see each other). So tutaonana means "we will see each other" (and note that "tu-" means "we," not "you"). There's a skill about this later in the tree, or if you have Wilson's Simplified Swahili, reciprocal verbs are chapter 55.