Making good use of idle time is a excellent pursuit. I suggest walking the neighborhood dogs for free or fee. This gives you exercise, makes you a contribution to your community and the most popular pack leader among your new 4 legged friend.
Find a passion or hobby! Mine is music and piano. So I like to find new music + create dj mixes (mainly Edm). I didn't have money for piano classes so I just used youtube
you can always go out in nature and identify the kinds of mushrooms you find, plants, incects, flowers, reptiles, etc. that's what i like to do every once in a while when i get bored of being home