When I first started growing, everything I read referred to 'pricking out' your seedlings but nothing actually told me what that was!
So I found out. And recorded this for you.
Some say to prick out when the first two true leaves appear (ie not the initial seed leaves you'll see when your seed germinates).
Others say to prick out when the seedling is as tiny as possible so that the roots haven't started to branch yet and therefore there is less chance of root damage when you prick them out.
Me - I'm too impatient to wait so I move them when they're tiny.
But as always with gardening - experiment. Prick half out when teeny, prick half out when they have their seeds leaves and see what works for you.
Then if there are any that haven't germinated yet, I simply place the seed tray back inside until they do.
(And yes, I will record videos with the correct video orientation going forwards!)