Answer to "Autofocus won’t focus close up"This is a problem probably not fixable by yourself. The most likely cause is a photoelectric sensor proprietary to Polaroid and not available in the market. It may even be no longer available as spare part by the original supplier. Maybe you can cannibalize a similar Poaroid Autofocus camera. The component is called Pickoff Assembly.
Answer to "How do I change the Battery in a Polaroid One 600?"Traditional Polaroid films like SX-70 and 600 include a flat battery within the film pack. This is evident when turning the film pack around by two cutouts in the plastic cover with a metalsurface visible. A good battery shaould show over 6 VDC when checking with a digital voltmeter. Newer film types do not include batteries any more.