He looked like an elder statesman in a YoutTube video I had watched before. He looked like an elder statesman in a YouTube video I watched before.

original is okay except for spelling but sounds more natural without "had" here

He looked like an elder statesman in a YoutTube video I hadrecently watched before. He looked like an elder statesman in a YouTube video I recently watched.

He looked like an elder statesman in a YoutTube video I had watched before. He looked like an elder statesman in a YouTube video I had watched before.

He looked like an elder stateman in a Youtube video which I had watched before. He looked like an elder stateman in a Youtube video which I had watched before.

After the meeting, I inquired withasked someone I knew whether the two men were the same person, and I sent the video link at the same time. After the meeting, I asked someone I knew whether the two men were the same person, and I sent the video link at the same time.

"Inquired" is not the best option since it's too formal and sounds very weird

After the meeting, I inquired withasked someone I knew whether the two men were the same, and I sent the video link at the same time. After the meeting, I asked someone I knew whether the two men were the same, and I sent the video link at the same time.

After the meeting, I inquired withasked someone I knew whether the two men were the same, and I sent the video link at the same timeover. After the meeting, I asked someone I knew whether the two men were the same, and I sent the video link over.

After the meeting, I inquired with someone, I didn't kneow whether the two men were the same, and so to clarify it, I sent the video link ato the same timeperson. After the meeting, I inquired with someone, I didn't know whether the two men were the same, and so to clarify it, I sent the video link to the person.

While the host was organizing the meeting, others discussed eternal life, and I couldn't understand most of them conversation. While the host was organizing the meeting, others discussed eternal life, and I couldn't understand most of the conversation.

An elegant man sat ton my right hand side; he spoke with the host at a proper pace with a beautiful tone. An elegant man sat on my right; he spoke with the host at a proper pace with a beautiful tone.

no need to say "hand side"

An elegant man sat to my right hand side; he spoke with the host at a proper pace with a beautiful tone. An elegant man sat to my right; he spoke with the host at a proper pace with a beautiful tone.

An elegant man sat to my right hand side; he spoke with the host at a proper pace with beautiful tone. An elegant man sat to my right and he spoke with the host at a proper pace with beautiful tone.

An elegant man sat to my right hand side; he spoke with the host at a proper pace with a beautiful tone. An elegant man sat to my right hand side; he spoke with the host at a proper pace with a beautiful tone.

My friend informed me they were different, suggesting that my inability tof distinguish between them might be due to I haven't seen thousands ofme not seeing enough North American people. My friend informed me they were different, suggesting that my inability to distinguish between them might be due to me not seeing enough North American people.

"inability to" + do something is always "inability to X" only say "inability of" if you are talking about a person's inability "(not) thousands of North American people" is an odd choice, not sure what your native language is but it's not an expression English speakers would use to convey the message of "not enough"

My friend informed me they were two different people, suggesting that my inability of distinguish might due to the fact that I haven't seen thousands of North American people. My friend informed me they were two different people, suggesting that my inability of distinguish might due to the fact that I haven't seen thousands of North American people.

My friend informed me they weare different, people, further suggesting that my inability tof distinguish might due to I haven't seen thousands ofthem may be due my lack of exposure to North American people. My friend informed me they are different people, further suggesting that my inability to distinguish them may be due my lack of exposure to North American people.

My friend informed me that they were different, suggesting that my inability of distinguish might due tohave been because I haven't seen thousands of North American people. My friend informed me that they were different, suggesting that my inability of distinguish might have been because I haven't seen thousands of North American people.

Both men actually sharve the same hair style and head shape. Both men actually have the same hair style and head shape.