You should talk to your doctor to get risks specific to you and your family. A lot of risks can depend on how healthy you and your partner are, both of your medical histories, etc. Best to talk to a doctor.
Otherwise just google it, the internet has a lot of information and rescources out there.
Everybody is different and the risks differ depending on health lifestyle and even hormone levels. I had my first at 29 and am now 35 and due the second in January. Had a blood test and Michael transluceny scan to ***** the risk for Edwards and downs and they came back 1:42000 so that's better than even some younger people!