You can go two ways for this implementation.
The first one would be very naive. Simply switch between 2 users, the first user would be X the other would be O. The program should be able to detect when one of the players has won or if it is a tie.
If you are feeling very confident implement AI for player O. Same rules would apply. Be mindful in your implementation because next week there will come some additional requirements.
Again I’ve created a Codepen for you to start with. Please submit your solution to this Google Form and happy coding.