Happy cartoons!

I'm sure you've heard of Bluey by now. Its so good, wholesome, and heartfelt. Everyone's watching, regardless of age.

Here's one of my favorites for happy feels: Kipper the Dog
Its a Pre-K show that's just super chill and pleasant. Feels like a warm blanket and cocoa. This one is definitely more for children, but its ok to indulge your inner child and tell it that things are okay.

For a more sophisticated palette, Hilda is the most criminally underrated animated mainstream cartoon in recent memory... that somehow got a full run regardless!
Three seasons and a movie on Netflix. Its beautiful and kid appropriate but definitely for all ages, and pretty damn serious a lot of the time. But its still rather uplifting in how a lot of things aren't problems, because Hilda is so spirited and determined in a way you can truly believe in.

My little Pony, new and old, really does the trick for me, but its not for everyone, of course. Pound Puppies and A Pup Named Scooby Doo also hit that vibe, though of the old shows mentioned, its probably the best written. (Never got into Care Bears, but it could probably work too, if you're looking for Sunshine and Rainbows)