Βλέπω and κοιτάζω are synonymes, they both mean "see, look". In some phrases they can be used interchangeably.
ex: Κοιτάζω τις φωτογραφίες. / Βλέπω τις φωτογραφίες. = I look at the photographs.
The difference between them is that βλέπω means "I realise the presence of an object with my eyes", whereas κοιτάζω means "I objerve, I pay attention to something."
Τι βλέπεις στην εικόνα; = What do you see in the picture?
Τι κοιτάζεις με τόσο ενδιαφέρον; = What are you looking at with so much interest?
Γυρεύω is different, it means "search for, seek" (informal)
Τι γυρεύεις; = What are you looking for?
Γυρεύω τα γυαλιά μου. = I am looking for my glasses.