It is common to see parents today send their children to learn foreign languages at early ages,especially when it comes to English,
Better you do not narrow down the scope of your prompt which talks about "foreign languages" in a broader perspective. Keep your intro more open . Also you do not need to have examples in the introduction. Body paragraphs are the places that you need to include examples to keep convincing your reader about your opinion on the argument.
Some educationists believe that it is better to do so before they enter secondary schools. I completely agree with them.
....
However, it is a fact that learning a foreign language early has its drawbacks.
.... well, if you support a certain position in the argument, keep supporting that in your body paras too. Do not talk about the other side as it doesn't help you justify your position.