I was the first out of my friendship group too.
I was 24 when I got married and 25 when I had DD.
A good friend had her baby 3 months after me.
My DH is 5 years older than me, and was ready for marriage and kids on the first date!

I don't think there is any right or wrong way, just different priorities and feelings.

Some of my male friends are approaching 30, and are still doing the same type of thing we were doing at 18.
They literally have not changed (or grown up) at all.