Another parent of a deaf child here. It is a scary time with a deaf newborn and you have a learning curve in front of you. The support you give your child will change at age appropriate levels and with the milestones they reach, as with their hearing peers, it's just that you will need to be more considered in your approach to communicating with him. Your baby will recognise and be able to sign before their hearing peers can speak. The more you do, the more they will learn from you. Put the work in to get the benefit of it and that sounds really sanctimonious and I dont mean it to be but you will wake up one day and not be so tired and so scared and know that your child just needs additional help and you need to get good at providing it.
Mr Tumble is great for engaging with Makaton, and you will have a teacher of the deaf who will help with how to communicate better.
As they get older you will learn more about what works and what doesn't. There are a lot of appointments, but this means someone's looking out for him on a regular basis and that's a huge support. Be prepared for the first shock of seeing a tiny ear wearing what seems to be a massive hearing aid. Ears grow, hearing aids don't. You are going to get some horrible comments from randomers, and you are going to have to advocate for your child from quite small so that he gets the life experiences that everyone else does.
My child likes bone conductive earphones to listen to music which play music through the cheekbone and mean earphones dont squash her hearing aids. Technology gets better all the time, and what is available now will be better again in 5 years.
Right now you have a newborn. Congratulations on your newborn. Enjoy your newborn and all the squidgy loveliness. In three months, start learning and doing the signs for food, drink, sleep, pig, cow, chicken, dog, car, train. When he's one watch Mr Tumble together. When he's two buy yourself a scooter too because he won't hear you shouting stop when you're in the park. Worry about what would be best at an age appropriate level, and adapt together. If your child was short sighted you'd go get them glasses. Deafness is a barrier that is mitigated by the people, attitude and the technology.
And that's too long, I'm sorry, but I wish someone had said it's going to be fine in those early days in a way I could have believed it. Congratulations again.