Updating Tags for Contacts with API v3

Hello:

I have a few questions concerning updating tags for contacts with version 3 of the API. Before I get to my question, some brief background:

I am in the process of updating our Constant Contact integration from version 2 to version 3 of the API. Without going into too much detail we are a choral group where people register to sing for a season (fall 2020 , winter 2020, spring 2020 etc). For each season we have been creating a separate email list in Constant Contact for the season. When people register for a season we use the API to add them to the mailing list for the season.

Recently we received an email notification from Constant Contact recommending that we use tags instead of creating a separate email list for each season. For example when someone registers for a season instead of creating a mailing list for the season the contact would be tagged with a tag for the season (for example fall-2020).

Checking the API documentation I did not see any documentation for tags. Should I be using the segments feature for this functionality? If so would the proper way to do this be to create the segment for the season in our Constant Contact account then use version 3 of the API to add or remove the contact as needed from the segment?

One last question concerning version 3 of the API. I am planning on using the endpoint which allows you to create or update a contact with the single method (https://v3.developer.constantcontact.com/api_guide/contacts_create_or_update.html). In reviewing the documentation I noticed that you are required to add the person to at least one list id. Do I need to create a list specifically for this? If I am using segments to tag contacts by season I don't really need to add them to a list. Is there a default list in our account I can use for this?

Hope all of the above makes sense! Please get back to me when you have a chance.