Congratulations on that all important first egg! Don't be too concerned if the first eggs you get have "issues". It takes a little bit for the assembly line to get completely in sync. You get a few rubber eggs, some misshapen or very small eggs, even some shell-less eggs until the kinks get worked out. If you aren't already, this is the time to switch them to layer feed. You can add some oyster shell in a separate dish free choice. They'll eat it if they need it and pretty much ignore it if they don't.
Since I have a mixed flock - active laying hens, a roo (or two or three or four!) some 7 week, 11 week, and 12 week old chicks - I feed a flock raiser. The roos and chicks don't need the calcium but trying to explain to each group that "this is your food, and this is YOUR food, and you guys stay out of each other's dishes" is pretty impossible. By providing what the layers need via oyster shell and chopped up hard boiled eggs with the shells, they all do very well.
And so the next round of your great Chicken Adventure starts - when they start paying their rent! Have fun!!