new user confusion

I installed the Google Analytics for WordPress plugin and watched the overview video at https://yoast.com/wordpress/plugins/google-analytics.

I went to “Google Analytics for WordPress Configuration”. There is no prompt to authenticate to my Google Analytics account. Instead all I see is: “Manually enter your UA code” and it displays a UA code. Does that mean it is already authenticated into GA somehow?

Originally I had the GA code snippet in my theme footer. Thinking this plugin would allow me to track visits to all the pages in my blog, I installed it, but in addition to the above, I do not see any setting for tracking all pages. Is that automatic from where the snippet is applied by this plugin?

https://ww.wp.xz.cn/plugins/google-analytics-for-wordpress/