There are some differences even in the first sets. Plants such as peppers, eggplant, and tomato, often have more long, narrow leaves.
Most of the seeds were started in cell inserts and they will be transplanted into peat pots when they start to set the second leaf. This is a tedious process, but if done carefully, you can plant almost all of the seedlings.
I usually have enough plants for me and enough of each variety to share. I always plant more than I think I will need in case something happens along the way. Sometimes they make it all the way to the hardening off process and then I lose them. But usually, I have a pretty good success rate.
Based on how the seedlings are coming along, I will be able to begin transplanting in a few days, a week at the most.