I adopted my Daughter when she was 12 (Days from turning 13) and my Son when he was 8.
We had been their foster parents for 987 days prior to adopting them. We mostly deal with normal parental issues, school, grades, boys for our oldest daughter, not wanting to do chores, etc.
I also have a biological daughter who was is now 2 (She was born while we were still fostering the older two and spent 2 months in the NICU).
The biggest difference if I am being completely honest, is the Adopted Parent/Child relationship takes a lot of work. There needs to be buy in from both sides, where they see us as their parents now, and we see them as our own biological children. I believe nature has its way of bonding biological children/parents naturally, but given they had a mom and desperately miss her at times, you just kinda have to take a back seat to that and let them work on that trauma and emotion, while being reassuring and loving.
But usually from the day-to-day stuff its fairly normal comparative I think to other families.
One of the biggest things that changed when we adopted them though is a lot of rules that social services has in place went away. For example, if we gave them tylenol, we had to document it, and the doctor had to approve it first. We had to document every Doctors visit. They were not allowed to stay home alone, or go to friends houses unless the friends parents where finger printed and background checked. Even things like birthday parties, we couldn't just drop them off at and leave, we had to stay there. Adopting them gave us the ability to actually parent, and give our children age appropriate freedoms and responsibilities. It was a huge weight off our shoulders.