The Positive things of adolescence:
Your maturity level will change as you reach your teenage and adult years. Your looks will also change usually for the better. You will start to like people by having a crush on them, or having feelings for them, etc. You will have better development mentally, causing you to make better life choices all around.
The Negative things of adolescence:
You will tend to have harder mood swings, causing you to have a shorter temper and usually upset or unhappy about more minor things in situations. You will go through...PUBERTY. Puberty is a stage where you deal with things I will not talk about but the process is...you know stressful, usually, after going through it you tend to look better, but right at the moment you are going through it, it is not a fun process.
Have a nice day!