How to get baby to sleep through the night?!

So my baby is a month old now, was born three weeks early! I have a 2.5 year toddler as well and I'm at my wits end! I cannot get enough sleep no matter how hard I try!

My baby wakes up multiple times throughout the night and it appears to be his most active time! How can I get him to sleep through the night?? He also spits up A LOT! Pretty much after every feeding, and he is exclusively breastfed. I would just like to sleep through the night..what can I do??

Any moms in similar situations that can offer some advice?!