Just going to say similar to Jo, teaching the sounds is a great way to start and introduce them to your little one. Lots of support online about how to say the sounds correctly. Most schools/nurseries use different Phonics schemes so possibly hard to use the same as their school one. Reading lots of books (and anything with words on tbh)and using the pictures to tell the story too is great 😊
My son has learnt some from watching alphablocks.
If you do any phonics make sure you say the sounds correctly plenty of videos on YouTube.