How to manage onboarding subscribers between Shopify and Klaviyo?

[Glassy_Al]

Hello, I am new to both Shopify and Klavio. I run a glassblowing studio which we're just launching on shopify. www.montereyglassworks.com. We are using the debut theme which comes with a very simple newsletter signup form. When customers sign up, they simply all get classed into a single subscriber bucket which have sync'ing to Klaviyo. I am at a loss as to how to modify the sign up form in two specific ways...

1.  I would like it to be a pop up when a new user visits rather than buried within the page.
2.  I need to allow the visitor to identify their interest...and to then identify this interest as a segment or tag. 

We will actually have three very different types of subscribers coming from different acquisition channels:

• Consumers that want to purchase products,
• Patrons that want to take classes or find out about visiting artist events, and finally
• Professional architects/design-builders that want to contract services.

Is this something done directly in Shopify, or is that done in Klaviyo (or some other email app) so I can use this tag/segment to create more useful specific email flows. I am not a coder, so was hoping this wouldn't require customization. Any suggestions where I could learn how to do this? I'm sorry to ask this on Shopify forum; Klaviyo's is a closed beta so I can't seem to ask there and their self help videos don't seem to address this segmenting as part of signup. I can't even make a new form that doesn't already have a segment on it. So, just confused and would appreciate any advice from a Shopify-Klaviyo user.

thanks,

al