However, I think itsocial media is a good pointway to get information by checking SNS.

I always check my Twitter to see the tweets about how to learn English.

No definite article here because you aren't talking about specific tweets about learning English. 'The tweets' would suggest that there are a limited number of tweets (maybe 5) about learning English

Although tTwitter is an efficient way for me to get information, sometimes some of them tweets are wrong.

Because Twitter is a specific company, it gets a capital letter. If you had written 'although tweets are an effective way..' then it would have been correct to use 'them.'

Today, I couldn’t concentrate much on my studies much due to my smartphone.

I have a bad habit of using my smartphone too much,. I often check SNS.

English speaking countries don't really use the term "SNS". Usually it's just referred to as "social media" or "social media apps". You would say "I often check social media" or "I often check my social media"

However, I think it is a good point to get information by checking SNS.

I always check my Twitter to see the tweets about how to learn English.

Although twitter is efficient for me to get information, sometimes some of them arethe information is wrong.