Explanation
According to the Salesforce Design System guidelines for button usage, the brand button should be used for the primary action on a page or modal, such as "Save" or "Continue". The neutral button should be used for secondary or tertiary actions, such as "Cancel" or "Back". The brand button should have more visual weight and contrast than the neutral button, to indicate its importance and guide the user's attention. Therefore, the best option for the Cloud Kicks custom component is to use a brand button for "Continue" and neutral buttons for "Cancel" and "Back". References: Trailhead: Systems Design with SLDS, Salesforce Developers:
Buttons, Lightning Design System: Buttons