Should I say "Alhamdulillah" twice if I sneeze twice in a row and was unable to say it after the first sneeze?

Praise (Alhamdulillah) is not obligatory when sneezing; rather, it is recommended, and scholars have agreed upon this. If you sneeze twice in a row and did not praise God the first time, you may repeat the praise twice. It is also prescribed for the one who hears you to say "Yarhamukallah" (may Allah have mercy on you) twice.