I've started my current Foundation Stage class on their coding journey and I used the following method as an introduction. All it needs is a white board and pen.
Write the following commands on the left side of a whiteboard and go through each with your class providing everyone an additional phonics lesson too. Explain to the children that these are commands, instructions that have to be followed if written them down in the program section of the whiteboard.
It's basically Simon Says without having to say Simon Says. If there are no commands written in the program section then nothing happens. Get your class to sit quietly awaiting their commands.
The children should quickly realise that the program controls their actions. I had originally written the jump command three times and my own followed this correctly. But I wanted them to offer a way to put the three jump commands together so I didn't have to write it three times. If you are four or five the words you might say are 'do it again' which a great answer. Explain that to do it again a program needs the repeat command. Ask how will we make sure the program is repeated three times? And what needs to be repeated three times? Without including the jump command at this point then nothing gets repeated three times. Programs follow a logical order and without logic the program is liable to go wrong, or have a bug in it.
Write a mix of commands in the program section and then using your finger, point to each command and your class should perform the action. It's quite a straightforward way to introduce coding to your early years class without having to worry about providing everyone a computer, tablet or other device.
I followed this lesson up with the brilliant Daisy the Dino app for the iPad. If this has helped you to start teaching coding to your own Early Years class then take a look at another post I wrote where I used Kodable.