Correct, start with household bleach as the "1:" in these dilution ratios unless the directions specify otherwise.

Make sure to mix a fresh batch daily because the disinfecting potency begins to dissipate as soon as you dilute bleach into water.

The same thing applies to the bottle of bleach itself, just slower. If you're serious about having a properly potent disinfecting solution and your bleach is more than, say half a year old, I would recommend that you buy a fresh bottle because bleach is cheap. If you can't remember when you bought a bottle because it's been so long, then definitely get a fresh bottle. Just use up the old bleach for less critical uses like laundry or whatever else you normally use bleach for.