One of the keys to resistance (weight) training is to allow for 48 to 72 hours between workouts for a muscle group to recover. Don't work a muscle that doesn't feel over 90% recovered. I've personally done 3 full-body workouts per week with good results. Just be sure to put at least full day of rest between each workout in that case.
Cardio? There's usually nothing wrong with doing 30 minutes of high-intensity cardio up to 5 days/week. Beyond that, you might be overdoing it. Again, it depends on your recovery.
Overtraining can be worse than undertraining. It usually is.
Lay out a routine here for us and we'll evaluate it for you.