It can be done, OP, but takes careful organising and forward planning. . You need to plan your life around the school.
While ds was at primary school, I applied for jobs that were within 10 mins drive of the school. That meant I could drop ds off at 8.40 and be at my desk at 9am.
DS went to afterschool club from 3pm until 6pm, allowing me to collect him at about 5.45.
That worked from reception until year 4. I was working for Vodafone and had a new boss who was truly nasty, knew I had to do school run, and kept organising 8.30am meetings to make my life difficult.
So I found another job, and carried on through year 5. Then after Xmas in year 6, the afterschool club decided it wouldn't run on Fridays, so for the last two terms, I took a late lunch on Friday, collected 10yo ds at 3pm, settled him at home with drink, snack, tv and phone, then went back to work from 3.30 until 5.30.
This was all before covid. Now I work from home 4 days a week, and school runs are easy. Plus I have a supportive boss, and work for a decent company.
For holidays, I took the same xmas as DS. The local council ran holiday clubs at Easter and in the summer, which DS liked, so I was always first as soon as their books opened. I usually booked 12-16 weeks in advance.
Plus I was friends with another single mum and we covered for each other for snow days, inset days and sickness.
By senior school you will be an expert project manager. You'll always refuel your car on a Sunday afternoon, have 5 clean school shirts ironed and ready to grab at a moment's notice, you'll know every bake sale, non-uniform day and school trip off by heart.😁