I hope you find something of interest in the language. And definitely ask any questions or share any observations you have.
As mentioned: I'm being a bit slow in getting Rebmu back up because of "reasons"...it always seems to raise questions in the language core. But I'll get there.
Learning the basics of Rebol is a prerequisite before Rebmu, though!
Then the Ren-C-isms push that into new territory, with a lot of new ideas and mechanics: