No, all the free days of the Starter Plan will be used without pauses once you activate them.
For example, if you earned 42 free days from the 9 referrals who connected their accounts, you can postpone activating them. However, once you click the Activate button in the Referral Program section of your dashboard, you will have all 42 days of the Starter Plan in a row; this subscription type cannot be paused or canceled.
To learn more about how free days accumulate, see Are the free Starter Plan days cumulative?