When and How should I use Whey Protein and HMB?

I'm 19, I recently lost around 50 pounds with a Low-Carb diet in which I'm still on, and I started going to the gym like 2 months ago, after I stopped loosing weight. I'm 6 ft tall and weight between 195 and 200 pounds. I still have fat that I would like to get rid of. I go to the gym Tuesdays, Thursdays and Saturdays starting with 20 min of cardio and then moving on to the weights. I just bought Optimum Gold Standard 100% Whey and Optimum HMB 1000 Caps and I really would like to which is the best way for me to use them so I can burn fat and grow muscle at the same time. Thank You Very Much and apologize for any grammar or syntax mistakes, as you can see I'm not a native speaker.