How to help my 13 month old sleep through the night?

I have a 13 month old who will not sleep through the night. He goes down for naps and bedtime just fine. For the past few months he’s been waking around 2 am. Recently. He’s been waking around 11pm and 2 am, then again a few hours later. We have another baby coming to join us in March, but honestly regardless I need help getting him to sleep better for the sake of my sanity. We keep his room comfortable, have a soft nightlight, a sound machine, feed him dinner, and try to make sure he eats plenty during the day.