You are missing Vanilla's .htaccess file. Sometimes this file isn't copied if you are using ftp to upload your files because this file is hidden. Make sure you've copied the .htaccess file before continuing.
Are you sure you've entered the correct database host name? Maybe you mistyped it? The database reported:
SQLSTATE[HY000]  Unknown MySQL server host 'Invalid' (74)
You must specify the name of the database in which you want to set up Vanilla.
Banner Title is required.