Take a close look at this https://premium.wpmudev.org/blog/how-to-create-wordpress-child-theme/ .
Note that your child theme’s CSS file has two required parameters. From the above link:
“The two necessary items in the code above are the lines starting with “Theme Name” and “Template.” The theme name tells WordPress what the name of your theme is, and this is displayed in the theme selector. The template tells WordPress which theme it should consider as the parent theme.”
I notice also that your ‘theme uri’ value has an extra space in it.
The header of the style.css file should look similar to the example in the above link.