I think the best way to teach about God is to model it. Pray with your child and make it familiar language. Say “Dear God, thank you for my dolly, mommy, daddy, ice cream,” etc. I usually include, “help me to make good choices” or something to that effect. My 2 1/2 year old will repeat what I say or try to babble her own. Then I recite an Our Father or Hail Mary to familiarize her with hearing them. She knows the sign of the cross and says “Jesus” pointing to a cross. She also recognizes Mary in statues or pictures. We have read her religious childrens books and there are also videos available. During Church, sometimes I whisper to her “look at Fr. so and so” or point out flowers or anything to guide her attention to the altar. I also include her in the service by letting her hold her own book to follow along, etc. I also use her baby brother to help- I’ll ask if she can show him how to pray, etc.
If you want to incorporate God into morals and discipline, I would say something like “that makes God sad when you do that” or something like that. On the contrary, say that “that makes God very happy” when the child makes a good choice or especially when they help someone else. Overall, I would just try to make the connection of common day to day things with God so the child realizes that God is connected with everything around them.