BOSTON — When Nicolas Doherty couldn’t get a ticket to watch the Red Sox play in the World Series in 2013, his mom promised they would get inside the park next time the team made it. So she got to Fenway Park on Monday afternoon to be first in line when tickets started selling Tuesday ahead of the series opener against the Los Angeles Dodgers, he said.

“She lived up to her promise,” the 15-year-old from South Berwick, Maine, said.

Hundreds of dedicated fans who skipped work and school to get to Fenway hours before the first pitch lined up in the cold for tickets, snapped photos, filled bars and took tours of the old ballpark.

Meanwhile, police said they were stepping up security measures, closing streets and deploying additional plainclothes and uniformed officers around Fenway. The teams will also play in Boston on Wednesday night before taking the series to Los Angeles.

While the cheapest tickets were selling online for hundreds of dollars, dozens of students camped outside Fenway were hoping to get a good deal.

Nick Karalekas, of East Providence, Rhode Island, said he got to the park around 6:30 a.m. to line up for one of the 100 $9 student tickets being handed out by the park. The die-hard Red Sox fan who attends Salve Regina University in Newport, Rhode Island, and teaches first grade said he told his school that he had the flu.

“I haven’t slept in two days, I’m so pumped,” he said. After the game, Karalekas plans to go home to rest for a few hours before returning early Wednesday to get in line for game two, he said.

Others, like Julie Miller, shelled out thousands of dollars to travel across the country to watch the teams play.

Miller, of Newport Beach, California, paid more than $5,000 for two tickets above the dugout in the hopes of seeing the Red Sox win at Fenway, she said. The World Series game she attended in 2013 was the one the Sox lost, she said.

The neighborhood around Fenway was a sea of navy blue and red, but some Dodgers fans also made the long trip. Dozens of Dodgers’ staffers, decked out in bright blue, lined up for a tour of Fenway on Tuesday afternoon.

Ernie Gritzewsky, a comedian from Los Angeles, was on the East Coast for work and was supposed to fly home Tuesday but decided to change his plans to go to the park in search of tickets.

“When the Dodgers made it into the World Series, I said, ‘I’m going to Fenway!’” he said.