newbie not sure where to start

I had some else develop my website on their server with wordpress. This person and I have are no longer in business together and I have moved the website to a new host. But since the new host did a server change I no longer have anything show up when I try and go into the admin page. (screen shows path in address line but page is blank completely) I am a complete novice at wordpress and do not have a clue as to where to start to learn where to learn and to figure whiether I can do this maintence myself or not. Any suggestions and or advice would be very much appreciated. I am in general used to be pretty computer savy but he kept all this in his computer and me in the dark.

Thanks for any feedback you can give me