Hello,
#1 As a dev the top-most thing to do to have an accessible site - write semantic & structure code, provide alt tags, add lang, title attribute, do not remove the outline from the CSS, make sure color contrast is passing, should have label tags and use Lighthouse and wave tool to assist your inaccessibility.
#2 For now my favorite is VueJS Gridsome (it has GraphQL support too) if I am looking for something UI Framework based otherwise I just go vanilla - it is superfast.
#3 I am pretty active on Twitter and Linkedin. I keep sharing my daily learning there and I keep interacting with devs there. Apart from these, attending Meetups help a lot and appreciating developers on their blogs, work, etc on DMs