Room and board are not qualified expenses for a tuition credit or tax free scholarship. R&B is qualified for a 529 Plan or ESA distribution. As such, TurboTax will not allow you to enter R&B until you have first entered a 1099-Q (the IRS reporting form for a 529/ESA distribution).
Later, in the educational expenses and scholarships section, answer yes when asked if you have book expenses. That will get you to the screen to enter Room & Board
