Sweet corn is a wonderful garden veggie and is always interesting to get started.
First, corn should be direct planted in the soil when temps are reliably about 60 deg. It does not do well when transplanted. A few years ago one of the commercial plant growers in this area tried selling individual corn plants for transplanting and failed miserably.
It is very important to carefully plant your seeds directly in the ground. They all need to be planted at the same time, same depth, and laying in the same direction. You want to insure the highest probability of each corn plant reaching the pollination stage at the same time, because they are wind pollinated.
You probably won't find this recommendation anywhere else, LOL, but it comes from many years of hands on growing corn in my gardens. If some is planted 1/2 inch deep vs 1 in vs 1.5 inches, you will have them coming up at different times. If you plant some one day and the rest the next, same thing. The seed corn has a definite shape...a pointed end and a rounded head and pretty much flat middle. Plant each seed preferably point down but for sure plant them all the same direction. Otherwise you may see some plants several days apart pushing up through the soil and that is NOT good for pollination and resulting production.
Its one of my favorite things to grow in the home garden...but it is very important to get it started right to enjoy a good crop.