Question mark folder and cmd+r doesn't help

Hello,

I wanted to reset my macbook lately, so i turned it off, booted it up and pressed cmd+r while it booted up.

I deleted my startup disk and restarted it. the problem is, everytime i boot up, all i can see is a folder with a question mark on it flashing on my screen. I`ve tried booting it up while holding cmd+r again but when i am told to enter my WiFi password and i doe so it says my password is wrong although i enter the correct one. Please help, my problem is very urgent.

Additional information:

Macbook: 2010

Version: Not quite sure but i think its Yosemite

Greetings