Let's break it down:
* Geia sou (Γεια σου): Hello (informal)
* pos eisai? (πως είσαι?): How are you?
* saga-po (σαγα-πο): This is a misspelling or a phonetic approximation of "s'agapo" (σ' αγαπώ), which means "I love you."
A correct and natural way to say this would be:
Γεια σου, πως είσαι; Σ' αγαπώ. (Geia sou, pos eisai? S'agapo.)
This translates to: "Hello, how are you? I love you."