I assign a number to the entire cross, then only give an individual seedling number to those that I save after they bloom. I would think you should give each seedling a pot if you're not going to put them in a bed so that they have room to grow and expand and bloom next year. You will find some seedlings are poor growers and just don't do well. The first pictures show some nice growth!
It will be fun to see the blooms!
