I'm an adult and I want to adopt new parents where can I go to find some?
Put an ad on Craigslist.
Adults can be adopted in the United States. Most often it is a situation like ours, where our oldest daughter became part of our family as a teenager. We adopted her after she became an adult, and could consent to her own adoption (she was 21 years old at the time). Another situation where an adult might be adopted is when a step parent has raised a child, and both of them want to make the situation legal after the child becomes an adult. Finding a random person or couple to adopt you is unlikely, and it is something you would have to find and arrange for yourself.
Thats not how adoption works at all. As an adult, you cannot be adopted, and even if you werent an adult, its the parents who do the adopting, not the child