It would be a fairly cheap Uber/Lyft, or their is also the public transportation option. Not "far" away, but too far to walk, in my opinion.
That being said... The CVS and Walgreens have just about everything you could ever need except clothes. Our first night in Anaheim was the night of a 2-day road trip. I'd lost my glasses, my tummy hadn't worked in days, I'd forgotten to pack my toothbrush, and I had left my conditioner at the last hotel. CVS was able to solve all those issues, and more! Had some little souvenirs as well. Park Vue has a store on site with some shirts, sweatshirts, sweatpants I think, among other souvenirs and general necessities.