Manager does not use journal entries much at all and definitely not for starting balances
Some of the Guides I would suggest starting with
Summary: Customize a business | Simplify Manager
Chart of Accounts: Design a chart of accounts | Build a chart of accounts | Add an account
Cash and Bank Accounts: Set up a cash account | Set up a bank account | Set up credit cards
Cash and Bank Transactions : Record a receipt | Record a payment | Import bank statements
Starting Balances: Set start date | Enter starting balances
Customers: Enter customers | Set starting balances for customers
Sales Invoices: Create sales invoices
Suppliers: Enter suppliers | Set starting balances for suppliers
Purchase Invoices: Create purchase invoices
Manager is compliant with Single touch payroll see https://www.manager.io/localizations/au/
Employees paid on a regular schedule (eg fortnightly) are best handled by recurrent payslips, see