by mistake I blocked my phone and I forgot the password and yahoo mail password

What do you mean blocked through find my iPhone? if you don' t remember your Apple id follow the instructions here: Change your Apple ID password - Apple Supportreset your email password through yahoo.

pedramparla wrote:

Dear sirs

I need your help .I have one 4s iPhone Mobile which by mistake l blocked through "find my iPhone"and now l can't remember the password and yahoo id ,l have only the invoice .would you please help me.

If you locked the phone and then forgot the password you will need to go to an Apple Store with proof that this is your phone (a receipt) and ask for it to be unlocked.

Apple will only help if you are the original owner of the phone. If you bought it used you will have to resolve this yourself.