We have a snuza monitor. It's a little clip you put on bubs nappy and it will vibrate/alarm if bub stops breathing. We took it with us to hospital (our bub has a heart condition) because we were worried about her when she left NICU to come back to the room. Funnily enough, we didn't use it. Her little noises and wiggles were enough.
But if you wanted a monitor that is simple and easy, you could get a snuza halo.
So sorry to hear about your first bub. Hugs.