Some people believe that teenagers should be required to do unpaid community work in their free time. This can benefit teenagers and the community as well. To what extent do you agree or disagree.

Answer:

Some people argue that teenagers should utilize their free time by doing (engaging in) unpaid community work, which will (are) be beneficial for them and society. (1) I firmly agree with the statement since it will not only help them to get the gain (use the most suitable words. Plus, write with brevity.) exposure of working in a team but also the community will get helping hands with modern ideas. (2)

1. Though the sentence is perfectly normal, you’ve picked a number of words from the question statement. There are better ways to write: Some people argue that, during free time, (use this as a modifier) teenagers should devote (channelize) energy to social causes, which benefit them as well as the community. (Note that I’ve not used their energy or their time. It is obvious that “their” exists. No need to write it.)

2. Violation of the rules of parallelism. In “not only X but also Y” construction, the first word of X and the first word of Y should belong to the same family. Here, the former is a verb, the latter is an article. Let us rewrite: …. not only help them …. but also enrich the community with modern ideas.

LR and GR issues in the introduction.

To commence with, (You’ve already commenced with the introduction.) teenagers will get ample exposure to working in a group of people, (You’ve already written this in the introduction. Don’t repeat it. This will count as a LR mistake.) which will endure (Check the dictionary meaning of endure. You can’t endure skills.) teamwork skills in them. (3) They will confront (why confrontation? why not communication and cooperation?) other people, which sometimes may cause their ideas to clash with those of (4) other members of the team. This situation It will let them learn the tactics to work in a group and grow as a team member (a missing word changes the meaning. Your sentence means – it will let them grow as a team. That’s incorrect.) by respecting the opinions of the other teammates. It will help them gain team working skills that These team working skills will help them in the professional world.

3. BP 1 should begin as: When teenagers work with Non-government Organizations for the betterment of society, they engage with people who have different skillsets and views. (Let us move beyond ‘a group of people’ that you mentioned in the introduction.) Communication and cooperation with such a diverse group may lead to a clash of ideas.

4. You can’t compare apples with oranges. Comparing their ideas with other members is incorrect. Compare ideas with ideas (those of).

I can’t see an example in the above paragraph. Discuss it with me over phone.

In parallel, (What’s that?) Additionally, the community will also get the benefit of young people working in a team. (5) Since a young guy is always energetic and enthusiastic, he can help society with modern ideas and new techniques. For instance, a teen working in a charity organization in India guided them (whom? An example’s nouns are independent of the idea’s nouns. Don’t mix them.) to make an Instagram page to reach out to a large section of the audience. The Instagram page not only helped the organization to reach out to more greater audience than before but also it helped them to raise considerable funds for feeding the poor people. Late on, the organization was bought by the very famous actor Salman Khan. (This does not add any value to your essay) 

5. This is too simple. Plus, you’ve stated this in the introduction. In this sense, the first sentence of BP 2 is very similar to the first sentence of BP 1. Let us combine the first and the second sentences. Additionally, when youngsters engage in social causes, the community also benefits from their energy, enthusiasm, modern ideas, and work methodologies. When Cry engaged grade 10 students from all schools of Mumbai (grade 10 = teenagers) to promote the cause of poor, destitute women, the youngsters used the power of social media tools such as Instagram and Facebook to reach an unprecedented audience in the city.

You need to write more both in BP 1 and BP 2.

To summarize, I believe that a teenager working as a volunteer to uplift the community work can be advantageous for him (weird construction.) and the community itself. (no need of this pronoun) The former can indulge in teamwork qualities, (You can’t indulge in qualities.) and the latter can rise through their (6) modernized ideas.

6. THEIR does not refer to any noun. Your subject is singular (a teenager). Their is a plural pronoun.