Oh okay — I did indeed uploaded the files from build directory to my admin folder.
I have to remain silent in my answers to: How do you start it? How do you proxy requests from your domain to strapi?
This is new for me so I have absolutely no idea 
As mentioned I followed the starter tutorial and feel it is missing crucial informations for newbies like me. I am used to gridsome and cmd’s like forestry. I must be missing a crucial step here.
Thanks for your willingness to answer my question though.
All the best