You are allowed to connect multiple shopify stores to one Gooten account. If you ever want to switch accounts, you will need to select the Log out button on the top right corner of the admin panel.
Once logged out you will be prompted to connect your shopify store, and log in. If you add your shopify store name and nothing happens, disable your pop up blocker, refresh your page and try connecting your store again.
NOTE: You are not able to connect a shopify account to multiple Gooten accounts