What would be the repercussions about lying about age in apple developer program?
If you just want to create apps, you can download Xcode and do that for free. You can even deploy the apps to your own devices. 

If you want to sell apps on the App Store, it takes more than just signing-up for the Dev Program; you have to sign contracts and bank agreements. You could be susceptible to charges of fraud and/or misrepresentation.