Wandering for the first time through an American shopping mall on Monday, 17-year-old Belen Ascariz said she was amazed at its size and the array of shops.

"It's quite unusual. It's very, very big," she said.

While she and three friends from Spain were mostly browsing through clothing stores for the moment, they vowed to return.

"We're going to buy a lot of things," she said.

At Westminster Mall, Ascariz and her companions were getting some of their first lessons about life in the United States as part of their studies at an international school that opened a year ago in Garden Grove.

After arriving in Southern California on Sunday, the 105 exchange students at YAGO School, who will live with American host families throughout Orange and Los Angeles counties, set out on Monday to begin improving their English and their knowledge of the United States with a trip to the mall--a strange but exciting place for the young Spaniards.

Before being turned loose among the shops and fast-food stands, many students said they enjoyed staying with families in Southern California and are looking forward to another summer here.

Mercedes Cordero, 17, who spent last summer at YAGO School, said she was "really looking forward (to coming back). I was counting the days. It was the family that made me want to come back the most." She also said she enjoyed returning to Southern California's beaches and theme parks.

While many of the students instantly fell in love with Southern California, they may chafe under restrictions imposed by local customs, according to the school's director, Christopher Bell. For instance, in Spain, teen-agers as young as 14 routinely stay out until 5 a.m. at dance clubs and wander the streets late at night.

"Spain is a \o7 late \f7 country, (and) for young Europeans, they find California very regulated," Bell said.

Still, the students remain enthusiastic about other quintessentially American activities, he said, noting that many of them learn to surf and skateboard.

"A huge number (of former students) loved this whole beach scene and surf scene. There's been a lot of them who have gone in for that in a serious way. Huntington Beach is very popular because it's near the waves," he said.

As a result, some students have quickly adopted American lifestyles, and "sometimes I wonder what their parents are going to think when they get off the plane," Bell said.