"O"

Ok so in the same lesson 1.3 there's another sentence " Oishii o mise o shitte imasu". There's 2 "O" in this sentence is this correct? or should it be "oishii o mise shitte imasu"? How do we know when we should put that "O" before any nouns? Thanks again

Oishii _o_-mise *o* shitte imasu _this o belongs to mise and has no grammatical meaning if I'm right_ *this o marks the object of the sentence, the word after that it stands, here the o-mise*

In this sentence, the "o" in "o mise" is a refinement "o" (お) and the the "o" after "o mise" is the object particle "o" (を). It's a speech refinement matter. So it's partly a personal choice whether you put "o" before these nouns or not. And it's not that you can put "o" in any nouns. It's a matter of learning them word by word.