First a pointed shovel.
Peeing is not much a problem.
Feces: a 5 gallon bucket and plastic liners. Plus, a comfortable seat...think toilet seats on top.
Food waste is an easy one.
Other waste like plastics may need to be buried.
Place? Depends on what type of waste and how much digging room and/or lawn and planter boxes.
Also, if you don't want too use your potable water, and goodly supply of baby wipes can be used for whore showers. Only need use them a couple times a week and only in certain body areas.
Other suggestions?
Pro tip on the 5 gallon bucket. Get some horse bedding pellets from Tractor Supply and use them instead in the plastic bag instead of kitty litter. They’re cheap, 7-8 bucks a bag and are far superior to the kitty litter. They have a pleasant smell and are very absorbent.
Cut the bottom out of the bucket, and put the bucket in a shallow hole. Bury the results, and the bucket is reusable.