Cerbot, available for all domains via http and https. Is it possible?

Question

Nginx

Found:
https://certbot.eff.org/lets-encrypt/debianbuster-nginx
As I understand it: this is a certificate (s) for all domains on the server with nginx. Right?

Actually, while I started preparing the server for tests, the following questions arose:
1) If I do this thing, will all domains be available via https and http? Or will it only be accessible via https?
2) If before ( https://certbot.eff.org/lets-encrypt/debianbuster-nginx ) there were already domains on the server with a certificate from cerbot (piece: 10-15 pieces) - will this conflict?

Answer 1

1. will depend on how you set up the webserver, and not on cerbot
2. at startup, cerbot will ask for which domains to create, or you can specify it manually. How cerbot will offer to merge domains also depends on the web server settings.