Noah and Khalil Volel enjoyed the final minutes of summer vacation, waiting in the car with their dad while their mom collected their schedules from the main office at the Devon Aire K-8 Center in West Kendall before the morning bell.

School started Monday, and like thousands of other students across South Florida, the boys, ages 8 and 6, were a little nervous, said their dad, Marc Volel.

“But, overall it’s like riding a bike. Once you get back to it, it’s like you never left,” he said.

Almost 350,000 students and 23,000 teachers got back to it Monday at Miami-Dade Public Schools.

Familiar rituals opened the year for some. Freshly pressed uniforms. That insanely early alarm clock. And paper crowns for 12th-graders at Miami Senior High and a few other schools.

The new year will bring inevitable change. For the school district, that includes:

• A fleet of new eco-friendly buses.

• 36 new magnet programs, like the video-game-themed program at Miami Springs Senior High School.

• A new program to report student accidents.

• A fledgling campaign for voters to approve a $1.2 billion bond referendum to fix crumbling school buildings and upgrade classroom technology. Voters will decide in November whether they want to borrow money through bonds and repay the money with property-tax revenue.

“So far, so great,” Miami-Dade Schools Superintendent Alberto Carvalho said of the new year.

He started his day at a bus depot, ate oatmeal for breakfast with students at the brand new campus of North Dade Middle School and toured the latest renovations at the historic Miami Senior High in Little Havana.

Carvalho said three main things were on his mind: more school choices for families; dealing with the still-weak economy; and the academic standards that state administrators are likely to raise again this year.

Fifteen-year-old Brandon Caneva took advantage of one of the new magnet programs. He joined the group of 29 students at the new video-game-themed program, called iTech, at Miami Springs Senior High School. Caneva, who is taking all honors courses plus a personal fitness class, said he was interested in video games and software.

“I want to do it as a career when I get older, and I like doing new things,” he said. He hopes to get involved in the film industry.

At MAST Academy, a marine-themed magnet high school, eighth-graders joined the campus for the first time and students from Key Biscayne took their designated seats, created in a deal between the school district and the village.

Administrators checked over new portable classrooms for the eighth-grade class. As the early-morning bicyclists crossed over the Rickenbacker Causeway, a stream of traffic passed as parents dropped off their children.

MAST administrators are still plotting out the needs of their students, who come from all over the county, so some of the school bus routes won’t be running for a couple of weeks.

In Southwest Miami-Dade, 4-year-old Bianca held her mom’s hand as they arrived at the Devon Aire K-8 Center. Dressed in her burgundy school uniform and sporting pigtails with pink hair ties, Bianca smiled when asked about her summer activities. “I saw Mickey this summer,” she reported.

Her mother and father, Jason and Edenia Friedman, prepared months in advance for back-to-school. “We bought the uniforms before the summer started and the supplies about a month ago,” Edenia Friedman said.

The first day of school also kicked off the district’s campaign for a $1.2 billion bond referendum. Carvalho highlighted the brand new campus at North Dade Middle School, which had to be evacuated two years ago because of safety concerns, and the continued renovations at Miami Senior High, which was built in 1927.

A major expansion and remodeling project, which will cost about $50 million, is two-thirds complete. This year, students can use a refurbished cafeteria and media center. The books are not on the shelves yet. But the original, scrolled steel trusses are no longer hidden, and the arched windows open to a view of the nearby Marlins ballpark.

On Monday, the girls’ volleyball team practiced in the newly renovated gym, which has air-conditioning for the first time in the school’s history.

At Hialeah Senior High, students walking up to school first saw recently pressure-cleaned stairs and a fresh coat of blue paint on the doors.

While the school got spruced up, Hialeah is one of the many Miami-Dade schools that need capital improvements. The

58-year old school is still lacking, teachers and students said, especially in terms of technology.

“It’s not even about having the latest technology,” said Daniel Reyes, a student. “We don’t even have enough computers for students to use on a regular basis.”

Miami Herald staff writers Jeff Kleinman, Ava Rivera and Michael Vasquez contributed to this report.