The types of benefits typically reported on a P11D include:
In Moneysoft - Click Employees - then click Employee Benefits. You can then select the employee and manually add the total benefits they get for the year. You only submit the P11D at the end of each tax year. The deadline is 6th July each year for the year previous.
To correct a P11D for prior years - you can attempt at the link below (online) to correct a P11D.
https://www.gov.uk/employer-reporting-expenses-benefits/reporting-and-paying
Over 22, (but under pensionable age), working, and earning more than £10k. These workings should be enroled
Aged at least 16, working, and earning more than £6,136. These aren't eligible for aut-enrolment but can choose to op into to a pension scheme that meets certain legal standards. If they opt in they're eligible for employer contributions.
Aged at least 16, working, but earnings less than £6,136. These workers can ask to become a member of a workplace pension, but there is no duty for employers to contribute.