LESBOS, Greece — When the conflict in Syria began more than four years ago, Mustafa Alabi was a 17-year-old soccer whiz who had quit high school to sew clothes in his father’s workshop.

But the war soon consumed his life. The shop burned, and rebels occupied his home in Aleppo. Sheltering with relatives, Mr. Alabi rarely went outside, fearing the army would draft him and send him to the front line.

Then, like many before him, Mr. Alabi fled to Europe, where he landed last month: 22 years old, with a backpack, a ninth-grade education and little idea what to do next.

“I have no specific hopes,” he said hesitantly, after struggling to buy bread here because he speaks only Arabic. “But God willing, after I register, if there is a way to play soccer. ...” He added, “Maybe I can sew?”