I have never had any of my plants blossom. I understand that avocado trees may take up to ten years to start blossoming, and commercial avocado groves usually graft their trees from already producing avocado trees. Currently, the oldest avocado plant I started is about six years old and has a stem about 3/4 inch in diameter. It is about five feet tall. Since I live in the northern US, my plants are outside for about six months a year. This isn't the ideal environment for a fruit tree. If my plants ever do blossom, I will post the information in my article.
I have had comments that discuss blossoms or fruit from avocado seeds that they, or relatives of theirs, grew. Most, if not all of those comments seem to be from regions where the plant can stay all year outdoors or is planted in the ground. I think it is certainly possible for a plant you start to produce fruit eventually, but you seem to need to be in a favorable environment.
I grow avocado plants from seeds as an attractive houseplant. Blossoms and fruit would be an incredible bonus, but I don't expect them. There are several nurseries that sell grafted avocado trees, and I recommend you consider getting a grafted plant if you really want to grow your own fruit.