Microsoft 365 features that help users manage their subscriptions, account settings, and billing information.
Hello,
Can you launch any of the apps, like Word, Excel, etc, then go to Files > Accounts > Update license, sign in again when prompted. See if that helps.
If not, you need to contact Best Buy to find out what's going on, to make sure the subscription is active and there's no billing issue, etc.
Microsoft explains it here regarding how subscription purchased via third party is managed: https://support.microsoft.com/en-us/account-billing/manage-your-microsoft-365-subscription-purchased-through-a-third-party-44749f45-4c0b-5d41-a73f-7634b8d2a763