Amongst a hundred other questions you ask yourself when you go to the gym like, ‘can my pants be seen through these leggings’, ‘is this top too tight’, ‘why is that person doing the same exercise as me and not even struggling’. You would have asked yourself ‘what should I be doing first, cardio or weights?’
Let’s keep this one simple, if you have to do them both in the same session (if you have to!) do a low intensity warm up i.e. walking on treadmill, row, then your weights training, then your cardio.
Know that this would not be optimal (training weights & cardio together) as when you do this ‘concurrent training’ it will blunt the rate of muscle growth. So the weight training you have just performed has been compromised. It is like driving with the handbrake on!
You will get more out of it in this order, but ideally you would train cardio and weights at separate times.
Then you just need to get your weight exercise order sorted! Look to train your biggest muscle groups first, then work your way to the smaller ones.