Is there any side effects on my body if i take amino acids to broaden my muscles while i am 19 years old?

Possibly Yes: Probably does not work and can lead to kidney problems, hypertension, possible seizures depending upon hydration status and type of amino acids.And again, probably helps nothing.

Depends: It depends, how much protein you are taking. Excess of protein might be a big burden on your kidneys, which are trying very hard to excrete the large protein metabolites burden. Be sure you're also taking a plenty of water to flush it off. It always good to try to keep a balance with the other healthy food (complex carbs and non-saturated fat).