I am so sorry you are going through this. 
I will be open and honest to help you prepare.
My baby was still born in 2015 at full term. A friend I met through a support group lost her baby at 24 weeks.
Take each moment as you can. And if all you can do is breathe that is good enough for now.
They will probably put you in a special and lovely room that they use for bereaved parents and you will be able to spend time with them later if they is what you wish to do. It is likely to be on the maternity ward so they can care for you as they need to. 
To take. Take something to wrap your baby in, maybe a change or changes too so you can care for them and take pictures to cherish in years to come. Take a teddy or something you want your baby to keep. Maybe something you can leave with your baby while they are waiting for their funeral, and you can then keep knowing it was with them. This may bring you comfort down the line. I have a blanket my daughter was wrapped in and it still smells of her, such a sweet pretty smell. Some hospitals have people who knit tiny baby clothes for precious babies born too soon.
I have a necklace with half a pendent and the other half was buried with her. This also brings me peace, it might be worth thinking of something along those lines.
Take lots of pictures and cherish every moment. Take as long as you need. They will probably provide a cold cot to rest your baby in to allow you to spend extra time with them as you need.
I found the Labour was actually quite lovely in parts. Sad but beautiful. The midwives were amazing.
There was a special bereavement midwife who came to speak to us and tell us of support available but I was in too much of a state to take anything in.
The hardest part of all was going to the bereavement services in the hospitsl and having to talk about what we wanted to happen with our daughters body, it never occurred to me that we would ever need to do such a thing. Our choices were private burial/cremation or the hospital would take care of it for us. If the hospital do it they normally wait for three people together and the grave remains unmarked, so give it thought. Initially we wanted the hospital to take care of it because I couldn’t even process what was happening and was daunted by trying to organise something like a funeral but in the end we did it ourselves and it was fine. We managed, we got through it. Five years ago I never thought I would get through the next day, week, month let alone year.
Allow yourself to feel whatever you need to feel. SANDS and CBUK are beyond brilliant in the support they give. Reach out when you feel the time is right.
Sending you and your baby much love 
hoping for a birth which brings you the most comfort in the years to come.