Is a message from a friend, who is unaware of the decision to travel for study and whose message contains information about the country one intends to go to, considered an indication among the indications of Istikhara? And what are the indications that may appear to a person after performing the Istikhara prayer?

It is not necessary for a sign to appear to the servant indicating the result of the Istikhara. Rather, one performs Istikhara, entrusts their affair to their Lord, relies upon Him, and seeks advice from sincere counselors. If their soul is at peace and their heart is open, they proceed with their affair. If it becomes easy, then it is good; and if it does not become easy, then goodness lies in something else. Let it be known that Allah’s choice for him is better than his own choice for himself. As Shaykh al-Islam said: "If one seeks guidance from Allah, then whatever their heart is opened to and whatever affairs are made easy for them, that is what Allah has chosen for them."