Rafael Hernández Airport (BQN) is Aguadilla's own airport, located on the former Ramey Air Force Base, and has direct flights from several US mainland cities including New York, Boston, and Orlando. Flying into BQN rather than San Juan saves you the two-hour drive across the island and puts you almost at the beach.
If you are coming from San Juan, PR-22 (the José de Diego Expressway) runs west along the north coast and takes around two hours in ordinary traffic, less early in the morning. Public transport between San Juan and Aguadilla exists but is slow; renting a car at either airport is a much better option if you want flexibility to reach the beaches and surf spots outside town.