Congratulations! Do you mind sharing which field office you're located in and what date In May did you file?
Depending on whether you filed under 3 or 5 year rule, make sure you take plenty of supporting documents in case your field officer asks you for them. You can look at the supporting documents file that the USCIS posts and start from there.
M-477.pdf (uscis.gov)
Study for the civics test as well but I've heard they will most likely ask you basic questions only.
What is your field office and when did you apply in May?
Congrats!