Hello @Snowcaster, welcome to the Let's Encrypt community. 
I suggest starting here Getting Started - Let's Encrypt
And for Certbot starting here Certbot Instructions | Certbot
Since you are asking for a wildcard certificate the DNS-01 challenge is your only challenge option.
Edit
Here is a link to a list of other topics on this community for Icecast
https://community.letsencrypt.org/search?q=Icecast%20order%3Alatest
Edit 2
There is a newer Certbot - Certbot 2.11.0 Release
Edit 3
And this maybe of assistance acme-dns-certbot-joohoi/README.md at master · joohoi/acme-dns-certbot-joohoi · GitHub
This list is starting to get dated but DNS providers who easily integrate with Let's Encrypt DNS validation