No worries mate. Fit a new set of Odyssey sticky pads (brake pads) and trim them correctly first. They stick like $hit to a blanket and if that's not enough go on eBay for an Odyssey slick cable before you change the caliper. My rider runs these and they are the best tenner you will spend on your brake to give it some serious stopping power.
Keep your tyres pumped rock hard as well. Most oldschool riders returning to Bmx make the mistake of thinking 35-45psi is the norm but ramps need you at 85psi typically (assuming your tyres can take it - read the side walls)
Enjoy the practice and get yourself to a ramp night in the near future for some advice. Check out the members events section for dates