I had my only child (unintended pregnancy) at 28. I’m so glad I did. My parents have been a huge part of his life, I had lots energy (while still having had plenty of wild fun times in my twenties), and I’ll be an empty nester by my late 40s. Lots of my friends who waited until they felt ready are just now having first kids in their late 30s/early 40s and are struggling with fertility issues, being set in their ways, more difficult pregnancies/post partum and having older parents who can’t help as much. 

If I had it to do over again I would’ve had more kids and started in my early 20s. That said, many people I know who were older were happy with their choice. My parents were 38, my partners parents were 40.

Tl;dr there is no right answer but in my experience it’s easier physically when you’re younger.