There are tons of bike riders in Amsterdam. Be careful not to accidentally step into or walk in the bike lanes.
From Schiphol (the main passenger airport), buy a ticket and take the train at the Schiphol Rail Link to head into the city to the main train station, right in the center of Amsterdam. The train trip takes less than ½ hour.
The language is Dutch, but most people in Amsterdam speak English; many also speak French and German.
Although Amsterdam is one of the safest cities in Europe, be extra careful especially when you are in tourist-packed areas (like the Red-light District).