If you are a member of their loyalty programs, you may have significantly more time to make a decision:
Before handing over your laptop, you sign out of iCloud and "Find My" and erase all personal data. Best Buy may refuse a return if the device is still "Activation Locked" to your Apple ID, as they cannot resell a locked device. Best Buy Return & Exchange Policy best buy apple laptop return policy
You will need your physical receipt, packing slip, or the digital version found in your Best Buy account . Dealing with "Opened" Laptops If you are a member of their loyalty