Q.Total Newbie Without A Green Thumb
I’m starting an initiative in junior high school to do quick 10 minute (or less) weekly planting of like onions, garlic. Things that need minimal effort. I don’t know the first thing about gardening and can hardly keep my two plants alive. Help!!!! What size planters should I buy? What’s a good nutrient to put? This is for Brooklyn school with absolutely no space and certainly no outdoors.

Certified GKH Gardening Expert
Those may not be the easiest plants to start with. If it will be indoors, you would benefit from a grow light. Containers should not be too large as they will keep the plant too moist. You can use a general, balanced fertilizer such as 10-10-10 and follow label instructions. Here is some info that may help:
https://www.gardeningknowhow.com/edible/vegetables/vgen/vegetable-gardening-indoors.htm
https://www.gardeningknowhow.com/edible/vegetables/onion/growing-onions-in-container-gardens.htm
https://www.gardeningknowhow.com/edible/herbs/garlic/growing-garlic-in-containers.htm