Bedtimes for Summer/School Year

Help me figure out sleep routines and schedules for my kids.

I have a 5-year-old and a 2-year-old. My 2-year-old has been fighting bedtime for a week or so, so I’ve been trying to figure out what needs tweaked for him, but my 5-year-old is starting kindergarten in September and her sleep routine will have to start changing too.

Current schedules:

2-year-old wakes up between 7:00-7:30, naps at around 1:00-1:30 and sleeps 1.5-2 hours, and goes to bed around 8:00 but takes forever to fall asleep.

5-year-old wakes up between 7:30-8:00, goes to bed between 8:00-9:00.

The kindergarten school day is 7:40-2:10 (ugh). School is an 8 minute walk from our house. Most days my husband can take her to school and pick her up and I can stay home with little brother, but there are days that I will have to cart him with me to do school drop off and pick-up.

I’m overthinking everything and need someone to lay out a plan of when both kids need to be in bed and when they need to be awake and when the 2-year-old can/should nap, and when/how to start transitioning to the new routine?