How do you sprout an avocado seed?
The tradional way is to stick 3 toothpicks into it and to place it with one end in a glass of water. It really doesn't matter which side. The root and stem know which way to go.
A better way is to place the seed 3/4 deep into a pot of good sterile potting soil.
Be patient, germination can take place anytime between 2 weeks and 3+ months.
I like to pinch the seedling afteer it has about 6 leaves to encourage branching.