Cargo Bikes of Camberville a super useful resource: https://www.facebook.com/groups/1029543797114243
Bike buses are groups of people who cycle together to school. See below for list of known active area bike buses. If your school is not listed, start one!
Argenziano School Somerville -rides are announced in school google group: https://groups.google.com/g/argenzianofamilies
Brown School Somerville: www.familybikeride.org/brownschoolbikebus
Peabody School Cambridge: https://groups.google.com/g/peabody-bike-bus/about
See video: https://twitter.com/cambbikesafety/status/1542486105781682176
Other organizers of bike rides which you may enjoy:
Cyclopolitan: https://www.facebook.com/thecyclopolitan/
Bike to the Sea: https://biketothesea.org/
Somerville Illuminations Tour: https://somervilleartscouncil.org/illuminationstour
Here are some links to organizations you could get involved with if you are interested in improving bicycle infrastructure and safety or promoting bicycling:
Massbike: https://www.massbike.org/
Arlington
Arlington Bicycle Advisory Committee: https://www.arlingtonma.gov/town-governance/boards-and-committees/bicycle-advisory-committee-abac
East Arlington Liveable Streets: https://www.facebook.com/East-Arlington-Liveable-Streets-132320803079/about
Belmont
Friends of Belmont Community Path: https://www.facebook.com/belmontcommunitypath/
Boston and Greater Boston
Boston Cyclists Union: https://bostoncyclistsunion.org/
LivableStreets Alliance: https://www.livablestreets.info/
Cambridge
Cambridge Bicycle Safety: https://www.cambridgebikesafety.org/
Friends of the Grand Junction Path: https://www.facebook.com/GrandJunctionPath/
Memorial Drive Alliance: https://www.memorialdrivealliance.org/
Cambridge Bike Give Back: https://www.cambridgebikegiveback.org/
Malden/Everett/Revere etc
Bike to the Sea: https://biketothesea.org/
Lexington
Friends of Lexington Bikeways: https://www.bike-lexington.org/
Medford
Medford Bicycle Advisory Commission: http://www.medfordbikes.org/
Walk Medford: https://www.walkmedford.org/
Somerville
Somerville Alliance for Safe Streets: https://www.sass-somerville.org/
Somerville Bike Committee: http://www.somervillebikes.org/
Somerville Bicycle Safety: https://somervillebikesafety.org/
Friends of the Community Path: http://pathfriends.org/
STEP: https://www.somervillestep.org/
Watertown
Watertown Bicycle and Pedestrian Committee: https://www.watertown-ma.gov/237/Bicycle-Pedestrian-Committee