WITHIN A WEEK OR TWO? AHHAHAHAHAHHAHAHAH, alright buddy, what your gonna need to do is, lift weights and do resistance training, and if your a skinnyfat, your gonna have to lose that fat, do lots of cardio, train everyday, mabye 2 hours a day, and you will get to your ottermode goal in mabye 2 YEARS

lol within a week or two? why dont you just fly to the northpole and ask santa clause for some muscle after feeding your pet unicorn with magical fairy dust given to you by tinkerbell.

Go to the gym. There are no miracle workouts that'll give you muscles in two weeks, but you gain muscles easier when you're a newbie.

Don't be so goddamn lasy.

Btw, eat everything in sight. You're not going to look buff when you're125 pounds.

erm all i can say is my height/weight is accurate for my age.

You just said that you were small for your physique? And you'll still need to eat more if you want to build some muscles.

small as in age and muscle for 5'9 yeah.
sounds decent. Any foods to take and avoid?

Eat chicken, low-fat dairy products, fish, eggs, vegetables
Avoid fast-food, sweets, and such
Remember that what's most important is that you rest and eat after you have excersiced. If you're lifting like a beast, but don't let your recover properly, you won't see any changes.

How many minutes a day should i lift/ do situps?