Hi there, thanks for reaching out and thank you for your kind words. See below responses to your questions:
1) I watched the video https://www.youtube.com/watch?v=FwhND8qX398 and then they said that the plug-in site kit is already enabled for AMP support, but I don’t see this on the site, maybe I misunderstood the video? Or do you need to install an additional plug-in for AMP? If so, which one is better to put?
The video demonstrates how to implement ads on your AMP site, and not specifically just how to implement ads via Site Kit. If you’re looking to implement ads via Site Kit only you may find this tutorial on our plugin website useful. You don’t need any other plugins other than Site Kit if you wish to activate Auto ads on your WordPress site. Site Kit inserts Auto ads code on both AMP and non AMP URLS alike.
2) to monetize with AMP, you need to customize something or will it automatically work if adsence is turned on in site kit?
Once you have an approved AdSense account and an approved site then yes, Site Kit can ensure ads are automatically placed across your site. This is dependent on whether you’ve allowed Site Kit to insert ad code on your site during setup. The configuration option to allow Site Kit to insert ad code is on my default.
Note that Site Kit can also recognize existing ad code on your site, if you prefer to manually insert ad code yourself.
3) by installing site kit, you can remove all metrics counters from the site, since site kit already has all this?
I’m unsure of the question, but I suspect you’re asking if other plugins that provide Analytics, Search Console or other reporting features are necessary if you’re already using Site Kit? If so then it’s up to individual users what other plugins they wish to use. Site Kit have provide some metric data that other plugins don’t. Likewise other plugins may provide insights that Site Kit doesn’t, so it’s up to individual users to choose.
Let me know if you have any questions on the above and I’d be happy to assist further.