Hello. Today I want to talk about SNSs. I don’t believe that SNSs are beneficial to our society because SNSs has some disadvantages for us. Although SNSs have a lot of advantages, they have dangerous sides/aspects, too/as well. SNSs enable us to connect with people all over the world. It is one of the advantages of them/one of their advantages. However, it makes us dangerous*. For instance, our personal information is/may be stolen by some hackers; this is the risk for all the people that use SNSs. It is especially important for teenagers because they tend to be targeted by the many kinds of crimes/tend to be a target for many kinds of crimes. Young people especially like/ Young people especially are likely** to use chat applications with their friends and family, so they have to be careful about that. To avoid/In order to avoid getting involved in a crime, we must learn the risks of SNSs. The other is that a lot of people are addicted to SNSs. SNSs are very useful for us to keep in touch with people all over the world. Therefore, we depend on SNSs. However, they often interfere with their/our*** daily lives. We have to communicate with each other face to face. We need to use SNSs correctly. So I don’t believe that SNSs are beneficial to our society.
*I don't quite understand what you mean here. Of course "it makes us dangerous" is grammatically correct and it makes sense, but maybe here you meant "it exposes us to some risks"...?
** I guess you mean "Young people especially like" but I also provided an alternative
***GOOD. By the way, you should choose between "we" or "they" and stick to that ;)