You cannot set the default order status as Checked In in the system.
We will need to customize this feature for you. Please raise a ticket to discuss further.
To resolve the issue,
Please set 'allow_url_fopen = On' and 'allow_url_include = On' in php.ini
Also please make sure that there issue no issue in your internet connection because many times this error arises due to a connection problem.
Also, make sure that your server configuration is compatible with QloApps. You can find the required configuration in this guide.
Please go through the guide very carefully. And if still there is an issue then please share your FTP details and URL on which you are trying to install QloApps over the ticket.