I have student visa and want to come to the US earlier than that 30 days allowed period of time.Probably one month earlier.Can I enter on visa waiver and before school starts re-enter the US by going to mexico or canada to activate the student visa? (which i was told i need to do).if i do so,do i need to buy one way or round trip ticket since i do not need to go nack to europe to re enter the US and how do i explain it to the immigration officer that i only have one way ticket? a while ago i learned i need to obtain change of classification and fill form I539 which takes months.is that so?
There are several issues here and the outcome is uncertain, so I would advise against it. Your idea of entering on visa waiver and then later "activating" the F-1 through reentry should work, but I am concerned about how CBP will view your entry without a return ticket. Of course, you must always tell the truth and the truth appears to favor you, but I have no clue how a CBP officer would view this entry on Visa Waiver.