NEW YORK (CBSNewYork) — It’s back to school for about 1.1 million New York City public school students.

Mayor Bill de Blasio and Schools Chancellor Carmen Fariña celebrated the first day of school Thursday by visiting students in all five boroughs.

De Blasio started off at P.S. 277 in the Bronx, where he escorted 3-year-old Joel to his first day of 3-K for All, a new program offering free, full-day childhood education for 3-year-old children.

“As a parent, I know how special the first day of school is and it’s even more exciting this year with the historic launch of 3-K for All,” de Blasio said in a statement. “Building on our work to make free, full-day, high-quality Pre-K for All a reality, 3-K for All will ease the financial burden on parents and give our littlest New Yorkers an invaluable head-start in life.”

The program was rolled out in Brownsville and the South Bronx.

The mayor also read to second graders at P.S. 46 in Harlem, and visited the New Visions Charter High School for Advanced Math and Science IV in Queens, P.S./I.S. 323 in Brooklyn and Curtis High School on Staten Island.

The school year began with a new policy that will provide a free lunch to every student.

Close to 75 percent of the city’s students qualify for free or reduced-price lunches, but many don’t get them because parents often don’t fill out the necessary paperwork.

De Blasio said this new policy will ensure every city student has the “fuel they need to succeed.”

Deputy Schools Chancellor Elizabeth Rose said this eliminates the stigma for some children who would turn down the meal rather than admit they were poor enough to qualify for it.

“It really creates equity for all of our students that every student can eat together in the cafeteria for free,” Rose said.

Fariña said the free lunch program will save families about $300 a year.

The program is not expected to add additional costs to the city.

Meanwhile in Brooklyn, a 17-year-old was in police custody after he was accused of bringing a gun to school.

Educators say the first day of school is the most important day of the school year.

“Oftentimes, I think the first day can be a time when a child comes back and it is really exciting,” psychologist Alexandra Stratyner told CBS2’s Erin Logan.

She shared some tips to help parents ensure that excitement level doesn’t change, which requires a long chat with your child – not just: How was your day?

“Did you meet anybody new in school today? Who was at the desk next to you?” Stratyner suggested. “Seeing what they found really fun or if there was anything that was a specific concern can be really helpful.”

But it’s not always that easy for all parents.

“It certainly takes a bit of talking to for me to pry information out,” parent Sarah Noda said.

“I want to know about the thorns and the roses,” said Nura Abdul-Karim.

Stratyner says the best way to do that, for all age levels, is to remind the child what he or she is good at.

“Being able to harness those good feels of strength and empowerment academically,” she said.

She says this will usually make the child more interested in a longer conversation.

Another tip is don’t focus on the negative yet – it’s too early. For example, fears of certain subjects and bullying.

“A month, three, four, six weeks — somewhere in there — and this is still going on, this is not just back to school jitters,” Stratyner said.

She says last but not least, don’t let your child notice if you’re anxious when dropping them off or picking them up. It could make matters worse or create a problem where there isn’t one.