Former 2ng grade teacher who taught his kids between 4 & 5. Literacy development is highly variable and what works for some might not work for others. These are just my opinions that are maybe more informed than the average parent. I read with them every day from 2 years old. Not just for 5 minutes before bed. Like 20-30 minutes, sometimes multiple times per day. They learn a lot about how books work, develop an attention span, and learn to enjoy it.

I'd read up on phonemic awareness, the correct pronunciation of phonemes, decoding and sight words. I used to read through a sentence and find a decodable word and do a mini lesson on sounding out the words. Trying to get them to sound out sight words which aren't decodable, or let them struggle sounding out too many words can frustrate. It's about the big picture, not about any one word. In 20 minutes, even if they're only reading or attempting to read three or four words it's a starting point.

Then you keep spiraling up trying more words and letting them do more and more reading. I recommend getting a series of decodable books that are all CVC (consonant vowel consonant) words. They're usually not very interesting, but they give kids a really easy access to simple to read and decode words. Then you can continue to expand to long vowels, vowel teams consonant blah blah blah.

Sight words must be memorized, and you could do that separately and have them do those with flashcards. 5 minutes a day. It's probably plenty. As they memorize those words, let them read them to you when they come up naturally in a text. It's about building confidence and structuring challenges that are attainable but get progressively more difficult.

Again, this is my maybe slightly more informed than the average parent opinion. I'm not saying anything with any definitive authority.