In order to import contacts, companies, or deals into HubSpot, you'll need to have your data stored in a CSV file. During the import process, you'll have the option to map the columns of your CSV to properties in HubSpot.
The files here are examples of what your CSV files should look like for contacts, companies, and deals respectively:
It is not possible to import more than one record type with a single CSV file. Different kinds of records must be imported separately. You can add and rearrange columns as needed. If you have a column that does not have a corresponding property in HubSpot, you will be prompted to create a custom property for it.