Help with Matomo Analytics for Wordpress Beta - 403s

Hi, I have today installed the Beta, yet cannot use it, as get a 403 when I:

Try to access Reporting
Try to add the Matomo short code [matomo_opt_out] to my Privacy Policy
Also, there is also no data showing as being collected so I think the install has failed somehow, despite it not showing as such.

I have downloaded the system report, but as I am not a developer, it means nothing to me!

Errors I can see, but don’t know how to fix:

shell_exec
You need to enable this built-in function.
set_time_limit
mail
parse_ini_file
glob
gzopen
md5_file

cron_sync 2020-02-03 13:32:03 Matomo is not set up yet => EnvironmentValidator.php:85; EnvironmentValidator.php:65; Environment.php:191; Environment.php:100; Bootstrap.php:74; Bootstrap.php:104; Sync.php:54; ScheduledTasks.php:168; class-wp-hook.php:286; class-wp-hook.php:312; plugin.php:544; wp-cron.php:138;

  1. Had visit in last 5 days No It looks like there were no visits in the last 5 days. This may be expected if tracking is disabled, you have not added the tracking code, or your website does not have many visitors in general and you exclude your own visits.

We did have visits in the last 5 days - so this makes me think it relates to 2)

Can someone please help? Thanks!