Download a Repo and Reuploading to Another

Hi, new to Github actions and yaml in general so I have question:

I want to download a repo on Github and reupload it to my repo. The repo I wish to download from is not private but my repo is private. I tried looking for tutorials but no luck so I hope there is a prebuilt yaml for this.

any luck?

Not very clear about your particular scene. Tested in my side, i use checkout step to get the public repo and then upload it to my empty private repo by using git commands.

For example:

name: Push 

    runs-on: ubuntu-latest
    - name: check public repo
      uses: actions/checkout@v2
        repository: OrgName/publicRepoName
        persist-credentials: false
        fetch-depth: 0
    - name: Create local changes
      run: |
        cat > test1.txt
    - name: upload repo
      run: |
        git config --local ""
        git config --local "github-actions"
        git add --all
        git commit -m "Add changes" -a
        git remote add origin2 https://$USERNAME:$
        git push -u origin2 master     
        REPO_KEY: ${{secrets.PAT_FOR_PUSH}}
        USERNAME: github-actions

Note: Make sure set persist-credentials: false and fetch-depth: 0 in checkout step. And prepare an empty private repo in advance.
If I misunderstood you, please correct me and describe your demand in more detail. Thanks