uploading theme - confused


Newbie here, sorry. From my wordpress admin page I uploaded and activated the framemarket theme. I want to use the gridmarket theme. When I check the page it does not have the theme look at all. What am I doing wrong and how do I fix this. I tried to do it through the FTP instillation instructions and have not been successful that way either. Any help is appreciated!

It says it is in parent theme and to activate the child theme. I cant find the child theme?? I tried uploading it again and it says the file is already there. How do I access that file.

I Also dont understand how to access the multisite admin. It is not in my drop down menu.