Setting up DNF on Yocto

I am using PetaLinux (or Yocto) as my systems OS. I built the image and have dnf as my package manager. However, when I try to install something, I get the error message: > Error: There are no enabled repos. So this means, my repo list is empty, I suppose. The question is, I want to be able to just install packages easily without always adding a repo or the url to the repo to install it. So is there some kind of URL I could source or add to my configuration file, where many common packages are linked with repo? I want to be able to just do something like sudo dnf install python3. Is this somehow possible? What do I have to do to get there? Thank you very much in advance! ## Edit ## I tried installing yum on my Ubuntu and then checking the repolist, but it is also empty. Where do I get standard repos from, so I can access many different packages?