Colleges for smart kid with so/so grades and few extracurriculars?

You should have many options. Do you know your approximate class rank? If you’re in the top 10%, then few colleges are completely out of reach. If your rank is lower, then a larger number of colleges become reaches (or possibly out of reach), but you’ll still have many options outside the “elite” schools. Have you looked up the admission requirements for public colleges in your state?

Does your HS have access to Naviance? If so, you can look up where students with similar GPAs and scores have been accepted.

What about your budget?
Have you run the online net price calculators for any colleges that interest you, and if so, have you discussed the “Estimated Family Contribution” with your parents? How much can they afford to pay?