I'm not convinced you have a significantly high metabolism or any physical problem with building muscle, so much as you have a low amount of patience. If you were as skin-and-bones as I was when I first started (and to give you an idea of just how skinny I was, my knees were thicker than my thighs), then at a decent rate of growth of about 1lb/0.5kg per week, you might notice something in your arms at about 3-4 weeks in, because from that starting point anything will be noticeable. If you're any less freakishly skinny, don't expect to see anything in the first 4 weeks. Give it 12 weeks of wholebody strength training and eating enough to gain 1lb/week... and others who haven't seen you during that time will probably start noticing you've put on some weight. Give it another 12 weeks of gaining 0.5-1lb/week and continuing to build strength all over, and you'll start seeing results. By this time you'll have gained ~18-24lb, and you'll probably be about ready to move up a shirt size or two, at least based on my experience.
Also, cardio chews into your calories. You need a calorie surplus to gain body mass and thus gain any appreciable muscle mass. You don't necessarily have to choose between cardio and building muscle, but if you cut the cardio and only did strength training, maybe you'd need 2,800-3,000kcal/day to gain weight, while if you did enough strength training and kept up all the cardio, you might need more like 3,500kcal/day to gain weight (in either situation, your actual calorie needs may be higher or lower than that, but those are just numbers to give an example based on average calorie needs). If 3,000-3,500kcal seems like a strikingly high amount, then that's another indicator that you don't have a high metabolism, you just aren't used to eating much.
EDIT: Oh, to address what you should specifically do in and out of the gym...
I won't write you a program, but there's plenty of good ones out there. Check the stickies. Here's some general guidelines. In the gym, do fullbody strength training 3x/wk. Your program should be built around movements such as deep squats, deadlifts, bench press, overhead press, rows and pull ups. Do 2-4 sets of most exercises, for anywhere between 5 and 15 reps per set. Focus on form first and foremost, and if you do a rep with bad form, the rep doesn't count (I hope that's incentive enough not to cheat your reps). Once you get all your target reps for an exercise on a training day, aim to do either more reps or more weight next time you do the exercise. Always warm up properly. That doesn't just mean get on the treadmill for 5min before lifting (although that can certainly help). Start all the major lifts with very light weights, then, over several sets, add weight and decrease the reps. Say your working sets are 5x100kg, the warm up on that exercise might look like this: 10x20kg, 5x40kg, 3x60kg, 2x80kg.
Outside the gym, eat, eat, and eat some more. Get a good amount of fruit and vegetables, healthy fats (which is pretty much anything other than trans fats or Canola oil), eat some nuts and eggs, drink milk and fresh juice, and eat meat from animals found on land, in the sea and in the sky. Consume 1g of protein/lb bodyweight/day, and create a calorie surplus of 300-500kcal/day above maintenance to gain 300-500g bodyweight/week. Sleep properly at night. Profit.
