The comments have basically covered this, but: It's a slightly weird parallel structure ("who shall not be at least 25, and been a citizen for 7 years, and who shall not be a resident"). The Constitution is not written in fluid 21st-century English. But the obviously correct way to parse the sentence is that no one can be a representative who isn't a 25-year-old or older who's been a citizen for at least 7 years; furthermore, no one can be a representative who wasn't a resident of the state they represent when they were elected.
With some parts of the Constitution (like the Second Amendment), the drafting results in actual disputes about the intended meaning. With other parts (like here), only one reading makes any sense. It's the same with the requirements to be President. The Constitution says "No Person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution, shall be eligible to the Office of President," which could be read as "you're not eligible unless, when the Constitution was adopted, you were either a citizen of the US or a natural-born citizen." But that's a silly reading, so "at the time of the Adoption" is read as only applying to "a Citizen of the United States:" natural-born citizens are eligible period, and people who were born before the US was a thing but were citizens by the time the Constitution was adopted were grandfathered in.