Hi amigo,
First off, welcome to Thunders. Make sure to read the Forum Guidelines and use proper capitalization, especially with all those I’s.
PE is a great idea for you, much the same as any exercise would be great for other parts of your body. Just because you are growing, doesn’t mean you can’t exercise and make the best of what you have.
The main thing for young newbies, is not to go overboard and stay within your limitations. Learn to do the exercises the proper way and start off slow and easy and build up your conditioning level.
The effect it will have will be you will build a bigger well functioning cock.