My third baby is almost 4 weeks old now.
You are likely to be tired. I found the first two weeks ok, because I slept between feeds, having not slept well in the final weeks of pregnancy.
I always find weeks 3-6 really tough. The sleep deprivation catches up to you and my babies didn't seem to sleep longer stretches until after 6 weeks.
The tiredness is a killer. Nothing prepares you for it. Make sure you have lots of easy meals to eat and snacks. Grocery delivery is your friend!
Mine were all formula fed, but they often wake in between feeds for wind or to poo, so try not to stress if they wake at totally random intervals.
My third wouldn't be put down for the first four nights, so sleep was practically impossible. We kept trying though and something clicked at 5 days.
Even though formula fed she is awakr every 2 hours for a feed, despite taking 130mls at three weeks!
Sleep whenever you can, let people help and bring food and remember that by 12 weeks things settle down a lot xx