mac pro freezes after i try to formate

Excuse my bad english but i run out of options here, so i tried to format my laptop and it went well expet the download stop at the end and it wont load so i tried to restar my laptop just to found out in the screen a big file with a question mark so I restart it again and and put my fingers on cmbd and r which lead me to a page to restart my network I choose it and i put my passord and I suppose to see somthing loading now but is there nothing!!! Please help me and thanks