need help with workout plan please!

meltesers

Hi, I would like help on making a workout plan, just a general idea basically.
I want to be doing cardio and strength training but im not sure where to start.
I have a treadmill at home and I will use that for cardio, i only do a minimum of 40 minutes interval training if I do go on.
I'm not sure if I should be doing both cardio and strength in one day, or should I be doing them on different days.
Also I need help on what strength exercises I can do at home, I dont have anything apart from dumbells and an exercise ball!
I want to be losing weight and my goal is to lose 15kg, do I need strength training? should I just do cardio? How much should I do each day? how many times a week?

thanks!