You've taken good steps by visiting those websites and reading through our documentation. Other resources that may help are listed below.
Background Videos on YouTube:
Or in general search YouTube for "FHIR Dev Days Blue Button" or "FHIR Dev Days CARIN"
Upcoming connectathons:
https://confluence.hl7.org/display/FHIR/CMS+2023+-+07+FHIR+Connectathon+4
(3x/year, Jan, May and Sept)
https://www.hl7.org/events/fhir-connectathon/index.cfm
https://confluence.hl7.org/display/FHIR/Connectathons
Choose a track relating to BB, like "CARIN IG for Blue Button"
Tracks run by CARIN, caveat that they are past basic Blue Button
These happen somewhat adhoc; none scheduled at the moment
https://confluence.hl7.org/display/CAR/2023+Connectathons
Other communities:
Subscribe to the "CARIN IG for Blue Button" stream and the "CARIN BB Explanation of Benefit"
https://confluence.hl7.org/pages/viewpage.action?pageId=171445832
Thanks and please reach out if you need additional support.
Kirsten Hansen
Product Manager
The Blue Button 2.0 API Team