1. What the message says, the PHP version on your server is not sufficient...So you need to either switch the PHP version or upgrade your webspace. Since you seem not to be that knowledgable about web stuff, ask your host.
2. You did not enter the MySQL credentials in the form indicated so Zenphoto could not connect to the MySQL server. Again ask your host for these credentials.
I really recommend to learn at least what PHP and MySQL means before trying to install an application on your server.