My apple tree has one flower. When will it start to grow?

I bought a young apple tree with no flowers on it and started to grow it a year ago. It is in a fairly sunny yet shadowy place and rain often comes., After a year, the apple tree has 1-2 flowers on it. I heard there was a stage when the petals start to fall, and they are right now. How long from now? will it take for the flowers to start growing some apples that are good for harvesting?