Learn everything you can about nutrition. Let that guide your decision making with food choices. It's not something that can be done here. Look for the USDA food database, download it, learn it.
Fat is stored via the insulin response. Study up on the gylcemic index. Lower index foods are generally better except post workout.
For weight gain, eat more calories than you consume. It's that simple. You can research base calorie requirements to figure out what it is that your base kcal should be.
Train for sacroplasimc vs muscular hypertrophy. You'll find some bad advice here, and it's best you research this for yourself. (I.e. high rep work for volume.) No real need for creatine (you can take it if you want, but, what you need is sarcoplasmic training, recovery, and calories. You'll need to learn food composition on your own.) You can get additional calories with high carb, high protein mixes. Read the label.
What I've said should empower you to take upon this task in a way that will start a life long learning process, hopefully.
For cardiac health the single best addition you can make is flaxseed oil at 3G to 6G daily. Also, fiber. Also, HIIT. It's important to keep your HDLs up and your LDLs down, with regard to your blood lipids. It's not o.k. to eat whatever you want because it builds in your vascular system and you end with a heart attack at 50 (that was more bad advice above). Fish oil is another great addition to your diet.
Cooper says a good multivitamin and flaxseed are a minimum effort to prevent heart disease.
Avoid energy drinks. They'll cause all sorts of problems with hypertension, prostate, and the like.
You need to eat...plenty of calories (lean protein, starchy carbs, and good fats). You're tiny for your height, which isn't all bad if that's your wish, but, without calories, you will continue to fail in your wish to make gains.