Layer feed has more calcium than other chicken feeds, but not more of anything else.
For now, I would just provide extra calcium, such as a dish of oyster shell. They will all take a few bites and throw some around as they decide what this stuff is and whether they like it, but after that each one should eat the right amount. Chickens are pretty good at eating the right amount of calcium when it is provided in a separate dish, so that works really well when you have some laying and some not.
When your current bag of feed runs out, you can get layer feed if you want. It is also fine to feed chick starter or grower or all-flock feed for their entire lives, as long as you also provide a separate dish of calcium (oyster shell).
Oyster shell is a common source of calcium for chickens. It is fine to give them eggshells as well, but people don't usually have enough eggshells to provide all the calcium their chickens need (each hen needs to eat about 2 eggshells for every 1 egg she lays.)