Hello, here are the translations.
1) Ciao. This greeting is informal. "Buongiorno" is formal.
2) Come stai? Informal. The usage of "Come sta?" is formal.
3) Sto bene.
4) Grazie.
5) Com'è andata la tua giornata? This question is not very often asked, but I think it's correct.
Have a good day,
Saïd.