I cannot recommend something specific but I recommend this website https://rubyandrails.info (no affiliation) that has a lot of categories and among those one easy to follow free course could be this one https://rubyandrails.info/youtubes/creatorplatform-xyz

In case you want to stay up to date with what is happening in Ruby world I am curating a free weekly newsletter at https://newsletter.shortruby.com (I took a two weeks vacation but will be back soon with new editions).