When you’re bulking the most important things are total calories and protein. If you are older and/or have a predisposition for fatness and/or have certain food sensitivities you need to be more careful about macronutrient breakdowns.
Since you are young, and seemingly in good health, and probably have enough to worry about trying to get protein into your diet, worry about that and total calories first.
Protein:
meat, fish, eggs, dairy (including supplemental whey powder)
Protein (lower tier):
Nuts, seeds, and beans
You want to be careful about not eating too much of the lower tier protein. You are going to find less protein per ounce in these, and your body will not absorb the protein as efficiently (in other words less actually gets into you of the already lower quantity). Also the lower tier proteins come with a lot of fiber (fiber is important but too much is not a good thing), are not complete proteins (missing some amino acids), and can be difficult to digest. Don’t avoid these but don’t make them your main protein source either unless you are a vegetarian.
1 g of protein per day per lb of lean body mass (or pure weight, I’ve heard it different ways) tends to be the guideline. Since you are bulking that would be the minimum. Divide that number by 5 or 6 meals and try to eat more than this final number at each one.
Once you figure out how to get a good protein source or two into each meal you can structure the rest of the meal around that. Since you are bulking you can pretty much choose whatever you feel like, though I’d suggest you make sure to get plenty of veggies and fruit in as much as you can. You still need fiber and vitamins/minerals.
Get familiar with the calorie counts of most of your foods and start totaling your daily eating to see if you are meeting your goals. Every day would be ideal but a couple days a week that are symbolic of an average day would do. If you need some extra calories you can always add some extra butter here, a bit extra salad dressing there, have another slice of cake for dessert, or get bacon AND sausage with your eggs.
Now, about what to bring to school. I don’t think PB&J will cut it. If you get the new double protein bread you MIGHT get 12 g of low tier protein from the bread, and then you add maybe 16 g of low tier protein from the peanut butter. That’s about 28g of protein. That’s not bad but remember your body is not going to be absorbing that as efficiently as animal proteins. If you must (maybe you’re poor or don’t have many options), this sandwich plus a pint of milk might make a decent lunch, plus some chips and some dried fruit.
If you CAN have something else, I would suggest making a sandwich with some sliced deli meat and cheese. If you (or your parents) can afford it get the preservative free kind but if not it should not be too bad. Put that on some heavy bread with your favorite toppings. Make a small salad (a cup or two of mixed veggies tossed with a little salad dressing) and put that in a sealed container with it. That plus chips, dried fruit, even a slice of cake, would make for a good solid lunch for bulking.