Doing just 15 mins of cardio after a workout can be linked with numerous health benefits (including, weight loss, improved mental health, and warding off illness)
It's going to take some time before you see results but trust the process (most experts say it takes between 3-6 months to see significant results)
Use progressive overload strategies when weight training (when you gradually increase the weight, frequency, or number of repetitions in your strength training routine)
Take progress pictures to document your journey (physical document of you achieving your goals)