Help! 22 month old sleep

My son is currently going down for nap around 1-2 because I have to pick up my daughter from school at 12 so I put him down for nap after we get home and have a quick lunch. He usually sleeps 1-2 hours. Then we go to bed about 7:45 but he takes 30-60 mins to actually go to sleep typically. I’m assuming it’s because he’s napping later but I’m struggling to get him down earlier since my daughter needs to get picked up middle of the day. The other problem is he often wakes up at 4:30 in the morning often. Sometimes I can lay with him and he will go back to sleep but it takes a while and sometimes he is just awake for the day and usually asking for food right away. He eats dinner at night and a half sandwich before bed so I don’t know what to do. Any suggestions?! I’m struggling with this schedule. He is sleeping through the night most nights now but it definitely doesn’t feel like this is the best schedule