My 21 month old doesn’t sleep through the night 😕

Help! My son is a great sleeper but gets up once a night every night wanting a bottle and to lay with us.. some would say this is no big deal but we are about to have baby number too and I want to try to do something so we will sleep through the night... protein shakes before bed?! Has anyone tried things that help for middle of the night hunger or just tips for sleep training at this stage? Thanks!