An overview of how to get started from scratch with COBOL
COBOL has a variety of resources to help both experiences programmers and beginners, though some might be obscure. Luckily, here's a compilation of some popular sources.
Beginning COBOL for Programmers
This book by Michael Coughlan covers the basics of writing COBOL all the way up to the 2002 standard. It also includes exercises to practice programming, which have been finished and gathered at this Github Repository.
Open Mainframe Project COBOL Course
This course covers the IBM dialect in the provided VSCode environment.