HI 
I had a ownCloud server I used to store important files from my hard drive. I've reformatted my hard drive, installed Ubuntu, and set up ownCloud again. Is there anyway for me to access my old ownCloud account which had my important files on it? Sorry if this is a noob question. But I'm noob to Ubuntu and ownCloud.
Did you format the harddisk of the server? Especially when you install a new system on it, it will be very difficult or impossible to restore data.
If you synced the files to clients, these clients might still have some data that can be recovered (make a backup of them before reconnecting to the new server!).