Dad is an American citizen. I am under 18 years old (born in 1995). Can I become an American citizen directly by immigrating to the United States?

You don't need any confirmation. According to your situation, as long as you enter the United States before 18, you will automatically become an American citizen.

You can apply for a passport directly.

Please consult the Immigration Bureau for specific explanation:

"A child born outside the United States is an American citizen after birth if:

The child was under 18 years old or unborn on February 27, 2006, and at least one of his parents was an American citizen. The child is currently under 18 years old and lives in the United States under the legal permission of permanent residence, and is under the legal and actual supervision of the parents of American citizens. "