It doesn't matter at what age you start, yes, but...
Well, unless you're a really patient person, starting at 10 isn't the best idea if you don't plan on cashing character cards for rebirths. As I've said before in my tips (if you bothered to read it), starting at age 17 allows you to wait for 3 weeks in order to 'freebirth' at age 20 rather than wait 10 weeks to rebirth starting from age 10.
But it's up to you.
Pinkie Pool's archnemesis: Oatmeal.