I have met someone online and now he wants to visit from nigeria

Please don't send him money. If he asks for money this is a scam.

He will soon ask for $ for passport fee, visa fee, etc. and after you send him the $$, you will realize this is another romance scam.

Tell him that you are going to visit him... and see what's next. Don't let yourself be come another victim of online scam. Good luck.

You don't need to do anything, they can get a passport and visa for about 300 total.

This is one of the oldest and most popular scams on the internet, they have rooms full of people there that pretend to be others to get people to send money. They will ask for unreal amounts, then the passport gets stolen, they end up in hospital and so on.