If you're wanting to upload contacts from an external source here is how you would do it. First make sure you have all the contacts and their info you are wanting to import on a .CSV file, then go to your Left Side Menu>Settings>Import Contacts.
from there you would select the contact type you are uploading,
You'll then select your file and upload to begin the importing process.
You'll then be brought to a mapping page where you can match the corresponding columns to what they're going to be in Spark. Take the screenshot above as example.
After accurately matching all columns. You'll then be able to add tags to the contacts you plan on importing as well as delete any found duplicates.
After adding any tags, you'll then be able to upload them to your account.
If you're having any difficulty with this process, please feel free to reach out in chat for further instruction and assistance.