Your credit score may go down during your first month of reporting.
As with opening any type of account or tradeline onto your credit profile, your credit score may initially show a slight decrease in your first month.
Everyone's credit report is different and subjective to many factors. There are so many variables that affect everyone's individual credit score, this value is not one we can predict and it different for everyone.
Rent reporting builds history into your credit file without adding debt because rent payments demonstrate responsibility and the ability to make large on-time monthly payments in which, the scoring models take that into account when determining scores.
Remember, credit is all about demonstrating history. So, typically, the longer you have a rental tradeline on your credit report, the better.