Hi there, @jeni-tan.
I'd be glad to help you get your data to QuickBooks Online.
You can use either CSV (Comma Separated Values) or XLSX (Excel file) to import information to QuickBooks Online. I can show you the steps on how to do that.
I've added this article to know more about the templates: Common questions about importing data to QuickBooks Online.
I've also added this article for your future task about managing your QuickBooks company: Get started with QuickBooks Online.
I'll be here if you need further assistance. Just tag my name in the comment section below. Take care and have a great day ahead.
As another option, you may utilize an importer tool
But if you migrate from a certain accounting system, you may consider purchase a 3rd party migration service.