By which do you mean old accounting records, starting balances, or new transactions. Depending on how your business operates you may need to enter suppliers/customers and invoices first
See
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
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
Importing records from an old to new accounting system is more difficult, and typically takes days work for someone with the motivation / willingness to pay. If that’s what you want see