I graduted in May of 2019 but my college was on a quarter schedule, so part of my tuition was paid in 2018. does this matter for the education deductions?

Tuition paid in 2018 for a course starting in the first three months of 2019 is counted as Education expenses for tax year 2018. The amount of tuition already counted for 2018 cannot be used again for tax year 2019.

If you failed to claim it in 2018, and did not already max out the 2018 credit, you can file an amended 2018 return.