Recently my F1 visa got approved I would like to enter USA 25 days before my school starting date. Because I want to visit Los Angeles for few days and then move to Washington DC (My school location is in Washington DC)
So my question is
May I enter USA through Los Angeles port instead Washington DC? or I must enter through DC because my school is located near by DC?
Do I have to face any troubles at Los Angeles Airport immigration?
According to the US state department, you can enter 30 days before the start of school with an F1:
http://travel.state.gov/content/visas/english/study-exchange/student.html
Because many people take connecting flights, your port of entry has little to do with your expected city of residence. If you enter through LA, they'll likely assume you're taking a connecting to DC -- if asked, you can tell the truth and say you'd like to sightsee for a few weeks.
Once you have your F1, you can enter or leave anytime while you have a valid and endorsed I-20. So if you want to do extended (> 30 days) sightseeing over a summer, you should do it next year while you are between school years. But your short 25 day excursion this year should be fine.
tl;dr: Up to 30 days before the start is fine, but stay on the safe side -- 25 days should be ok. Port of entry does not matter.
You can enter from any airport.
I got my F1 for a school that didn't have direct flights from UK, so I did immigration at Dallas because that was the closest flight I could get.
The immigration officer will not ask for your on-going (forward) journey - they did not ask me. Good news too, since I hadn't booked my onward ticket because I wasn't sure if I was going to fly or drive there.
