In 2018, Gabriel Tetrev opened up a 700-square-foot space on Oak Park Avenue to make and sell his ceramics. But after getting a lot of requests to teach classes, he searched for a location that would allow him to do so. “When people see a wheel in the window, or you working with clay, they want to do it themselves,” said Tetrev, a 28-year-old who grew up in Oak Park. While some don’t want to spend money on other peoples’ pottery, “an $80 one-t…