How can i get bigger/stronger?... :(?

Well your muscles will be fine but do not over do it because you can create scar tissue in your muscles. For example if you are really sore in you biceps, DONT do any bicep workouts, but I'm sure you know that. Supplements all depend because there are lots of things in them. I would recommend pure whey protein or six star protein. With the creatine you wanna use this before a workout because it will provide your muscles with the energy it uses instead of nothing at all but do not take to much of it. Go easy with it. Post workout your gonna want healthy sugars like fruits and things. And by post workout I mean right after because your body has used the nutrients it had and now you need to replenish them. I would recommend again fruits Gatorade water... Etc. After maybe an hour or so you wanna take the protein supplement... Again DO NOT over do it. because your kidneys can only process so much. Also WATER WATER WATER DRINK NOTHING BUT WATER OR WATER BASED DRINKS LIKE GATORADE but careful what you drink. Protein intake usually is your body weight for guys. So if you weigh 120 then that's how many grams of protein. But depending on your age, younger guys like teen years you wanna be more careful about since your still young and developing. I would recommend going to power1k.com it has tips and plans and diets. Good luck