Sleep issues

Hello! My 12 month old nurses to sleep for naps and bedtime. He sleeps on my lap for his naps and sleeps in his crib at night. However, nighttime is such a huge issue for us. He’s up an average of every 2 hours and need to be nursed back to sleep most times. However, sometimes he will nurse but not fall back asleep after. Not sure what to do. I know he doesn’t need to eat at night but doesn’t he still need milk alternative? I just started trying to introduce milk via sippy cup- he is only used to water and just spits the milk out.... wondering if night weaning will help but do I need to give him milk somehow at night? Help! I’m so confused.