Instalação de Mysql Database Extension, Mcrypt/Encryption Extension e Php Short Open Tag: < em Wordpress

Instalei o Plugin OptimizePress, porém ele não está funcionado como deveria.

Buscando mais informações, descobri que está dando erro em três aquivos, que são:

1) Error[ERROR] MySQL Database Extension
Missing MySQL extension. OptimizePress needs the MySQL extension for PHP. This will add MySQL support to your installation of PHP, allowing MySQL database communication.

Please consult with your web hosting company about this message.

2) Error[ERROR] Mcrypt/Encryption Extension
Missing Mcrypt extension. OptimizePress needs the Mcrypt extension for PHP. This will add encryption support to your installation of php, with a variety of block algorithms; such as des, tripledes, and blowfish.

Please consult with your web hosting company about this message.

3) Error[error] php short open tag: <?
php v7.2.17-0ubuntu0.18.04.1 MUST be configured with short_open_tag=on in your php.ini file. Please check this article for further details. Or, consult with your web hosting company about this message.

You are currently running PHP with short_open_tag=off.

Então eu gostaria de está resolvendo isso mas não tenho a mínima ideia de como fazer.