Hi and welcome,
Forms do not have to be uploaded to Aggregate before they are used. They can be manually added to Collect. Simply place them in the /odk/forms folder on your Android device’s SD card.
From: https://opendatakit.org/use/build/
You will need ODK Aggregate to visualize/receive/send data.
Here is a detailed guide for the installation and setup:
Don't forget to Introduce yourself here!