Don’t worry too much.
There’s nothing wrong with cardio before your training or after. Pick one that suits you and your method of training better.
If you’re still confused, let me help your think a little.
If your actual training is heavy, and hard-hitting-you probably need all the energy you can get during your session. So in cases like that, it’s probably better for you to employ your cardio session after your actual workout.
If your training is light-weight, easy to do, but very tiring (endurance-wise), then maybe doing cardio in the beginning can be beneficial for you, as it warms up your entire body, blood-circulation gets better overall.
Personally for me, I usually like to cardio on alternate days (rest days), as it boosts recovery and optimizes fat loss without messing up your gains. I like to do LISS (Low Intensity Steady State) cardio to supplement my workouts. On my training days, I train hard and heavy, so I get the most benefit for my muscle growth.