Is it normal for me to look at my friends' bodies. Especially if they are more developed than me. Does this mean I am gay?
It means you're curious. You are in the process of growing. You want to know what the next set of changes will do to your body. You wonder if you are developing at the same rate as other boys. You might even be a bit envious of boys who have developed sooner than you, wishing your body had gotten to the point these other boys have reached or were in as good of shape as they are in. But none of this means you are a homosexual.
Homosexuality is when you have sex with someone of the same gender. So while curiosity is simply normal, a strong desire to have sex with another boy would be wrong. Envy of another is also wrong because it will cause you to act improperly toward that person.
You will find that our language is being manipulated by people with agendas to change society. People have forgotten that homosexuality is choice to sin. It does not define who you are. Even people who have made a mistake in their choices and went against God's teaching can choose to start doing what it right. It is hard to do right after doing sinful things for a long while, but it is never impossible. The better way is to never go down the wrong path.