Great job accidentally gardening! Garlic needs to grow a long time to build a good bulb. I let the greens grow over winter. Then in early spring it tries to flower, but you should cut that part away early (it's called garlic scape and is delicious sauteed in butter). Then once greens come back after that it should be nearing harvest time, it's neck should peak out of the soil like carrots when they're ready to harvest. But defer to the packet instructions if it's something other than hardneck! Good luck fellow gardener!