Cardio is not complete trash but given your situation, your friend is right.

https://www.youtube.com/watch?v=LL28u397kTI

While you're overweight, concentrate on lifting heavy and hard to increase your muscle mass. The only cardio I would recommend is walking 30 minutes 3 day per week right after your weight training (there are exercises you can do for shin splints). When you're happy with your muscle size (you have good definition in your chest, etc.) you can start to cut (and add cardio if you please).

Have you've calculated your BMR and are you keeping tracking of what you're eating? Because if you're overweight, you're lifting, you're eating clean, and your net caloric intake is near your BMR or slightly above it, then you should be gaining muscle mass and losing fat (emphasis on fat and not weight). You don't have to do cardio, even when you're cutting, as long you're reducing calories.

Personally, I like cardio as it helps me reduce stress but I do it when I'm cutting or at a steady state and have eaten a bit too much.