OOTB (out-of-the-box,
in Infopath form template one can either/or
The latter (creating multiple sharepoint list items from from an Infopath form)
can be done only if one choose in Infopath Designer, on ribbon
- File > New > Sharepoint List > Design Form and during followed Data Connectin Wizard have chosen "Create a new Sharepoint list" and "Manage Multiple List Items With This Form" .
Note that this cannot be changed later if these options were not chosen during Infopath form (and simultaneously Sharepoint list) creation
Then you can create data fields in Main Data Source and drg'n'drop it on Design surface of Infopath template form.

Fug.1. "Sharepoint List" template in IPD

Fig.2. Create a New Sharepoint List Form in Data Connection Wizard to a sharepoint list

Fig.3. Manage Multiple List Items With This form (Data Connection Wizard in Infopath Designer to a sharepoint list)
Fig.4. Creating Multiple sharepoint list items in repeating section of Infopath Sharepoint List Form

Fig.5.. Result of (multiple) New Item creation in repeating section of Infopath form