Here's a few blogs/sites/channels who post hopeful news:
— reasonsforhope (Tumblr)
— hope-for-the-planet (Tumblr)
— mindblowingscience (Tumblr)
— sambentley (Tiktok) or itssambentley (Youtube)
— Mossy Earth (Youtube, you can donate to the org too)
A few other good news providers (not blogs):
— Fix The News (weekly newsletter)
— Good News Network (website)
— Good News UK (subreddit)
Cool initiatives you can participate in from your couch (international edition):
— Fish doorbell (seasonal, open the door to let fish migrate)
— MapSwipe (update vital geospatial data in this collab between Doctors Without Borders and several Red Cross organizations)
— Zooniverse (platform for people-powered research, plenty of projects to chose from)
— Old Weather (transcription of old ship logs to help climate scientists study old weather patterns)
— Foldit (solve puzzles and contribute to scientific research on protein structure and function)
— Fathomverse (play the game and help discover new ocean life)
Cool initiatives you can participate in from your couch (US edition):
— CitizenScience (another platform for people-powered research, plenty of projects to chose from)
— Smithsonian museum (transcriptions)
Cool initiatives you can participate in if you go out sometimes (like to work or in your yard):
— Monarch Butterfly Project (plant milkweed, if you live in a place where Monarch Butterflies also live)
— Cornwell Lab (learn more about birds, with links to two bird watching apps to help survey their range)
— iNaturalist (take photos of plants and help survey their range)
One thing important to know is that you'll never be the only one in charge of a project. If you can't focus for long or participate for long, it's fine! Even a little bit of help is still help.