If the crescent moon of Ramadan is confirmed to you on Thursday night, that is, the first day of Ramadan is…

If the crescent moon of Ramadan is confirmed to you on Thursday night, that is, the first day of Ramadan is Thursday. What is the ruling of the one who has been proven to him the beginning of the month of Sha`ban through what he has heard from the believers, that someone has seen the crescent and he can depend on him? Accordingly, he fasted on Thursday as the first day of Ramadan, because on Wednesday it was the completion of the month of Sha’ban, and on the morning of Thursday and his intention that it was from Ramadan, but it became clear that the majority of scholars in our country did not confirm that it was from Ramadan, so he became suspicious: 1. What is the ruling of fasting if this day is not proved to be part of the month of Ramadan? 2. If he changed his intention in the morning of Thursday of Ramadan to what he missed of old fasting, or from Sha'ban or the matter he is heading to? 3. If doubt occurred that this day is not from Ramadan, but that doubt occurred after breaking the fast of this day, what is the ruling on fasting this day? 4. If the crescent moon of the month of Sha’ban is proven to him such that Wednesday is a completion for the month of Sha`ban; nevertheless, he fasted on Thursday with the intention of Qadha what is missed of old fasting, and not from the month of Ramadan?