SA Pay

Going to be interning at an MM this summer in nyc. Just curious about pay after seeing some posts. My offer letter states an annual salary, but also states my hourly rate and that I qualify for OT rate. Also mentions im going to be paid a fixed amount biweekly. Does this mean im only getting the fixed amount payments though and not on the hourly basis? Will I not get OT pay then? Just wanna make sure I can plan out finances for this summer properly. Any help would be appreciated, thank you!