@renatozechetto Hello and thank you for sharing your lovely painting 
!
I've heard others comic artists say Wordpress's MailPoet plugin is great for newsletters. I don't have any wordpress tips, but https://comixcleric.com is coming up as a wordpress alt~
To reach people,you can check https://fedi.tips/fun-and-useful-hashtags-to-follow-on-mastodon-and-the-wider-fediverse to add to your posts!
There are also groups you can post to to share your artwork more directly to anyone that opts into following the group https://about.fedigroups.social/directory