|I was able to get the seed from the mango, but I'm not sure how to plant it.|
Growing a mango from the seed in a store bought fruit is generally not that successful. The mangoes may have been treated to sterilize the seed or kept too cold to allow them to remain viable. Such seed are often discolored a grayish color. If you can find fruit that has not been rendered unviable the technique for sprouting a seed is to remove the outer husk by carefully cutting around the outer (convex) edge with a knife so as not to damage the seed kernel inside. Then plant the seed inside before it dries out. Set the seed into a seed starting mix with the concave edge down and the convex edge sticking about 1/2 inch above the soil level. Keep moderately moist and it should germinate in a couple of weeks if the seed is viable and temperatures are warm.