Trying to move a WP site - Problems

I am trying to move a WordPress site from a local server to a web server. I have uploaded all the files via FTP to the web server site root. I have exported the local database, I have created a new empty database on the server and imported the exported/dumped database. No problems there. I have read that there is supposed to be a file named functions.php that I could add two lines of code to, to change the URL if necessary, but I can't find a functions.php file within the files on the web server. (1) Do you know where that would be located, and (2) the theme is not displaying, so I'm not sure what to do next. Can you help me? I have also updated the config.php file with the database name, user and pass. I don't know what else to do. I can't login to the site even though it does partially display content. Is there any other information I can give you so that you can help me?