I haven't been a dad super long, but if I've got any advice for y'all, it's this:
Give love and kindness and patience. You and (especially) your child's mother are your kid's entire world and all they know. You are all they have in this big, scary world. Be patient. It's easy to get frustrated when you're sleep deprived, and your entire life you've known for however many years or decades has changed. It's never going to be the way it was again. Own it and love it. I tell myself this from time to time, so I'm not claiming to be an expert by any means. Just some good advice.
Also, the head coach I work with said something that has stuck with me: isn't amazing how much we love our kids more and more every day? Just imagine that's how much God loves us, and even more. Having children has made me feel God's love that much more, and maybe even get close to understanding it.