Today I talked with a bBritish boy on discord.

I helped him to practice his Spanish and it was really fun.

いいですね！

I am from Mexico and he is from England, we are so there's at seven hours of difference.

I would never have thought that it were even possible for me to talk with somebody who is not from the American continent but I did it.

You nailed this subjunctive tense sentence - hooray for you!

Today I talked withto a bBritish boy on discord.

More common usage :)

I helped him to practice his Spanish and it was really fun.

I am from Mexico and he is from England, we arhave at seven hours of time difference.

Correct usage!

I would never have thought that it wereould even be possible for me to talk withto somebody who is not from the American continent but I did it.

Hypothetical possibility requires subjunctive would

Today I talked with a bBritish boy on discord.

I helped him to practice his Spanish and it was really fun.

I am from Mexico and he is from England, we arhave at seven hours of time zone difference.

I would have never have thought that it were even possible for me to talk with somebody who is not from the American continent, but I did it.

Today I talked with a british boy on discord.

"guy" might sound a little more natural, as "boy" usually denotes a young child, but it's not extremely wrong.

I helped him to practice his Spanish and it was really fun.

I am from Mexico and he is from England, we are atso there is a seven hours of time zone difference between us.

I would never have thought that it were even possible for me to talk with somebody who is not from the American continent but I did it.

Today I talked with a bBritish boy on dDiscord.

I helped him (to) practice his Spanish and it was really fun.

I think "to" is grammatically correct, but removing it feels more natural to me.

I am from Mexico and he is from England, we areso there's at seven hours of difference between us.

I would never have thought that it were evenould ever be possible for me to talk with somebody who is not from the American continent, but I did it.

This correction is hard. The original sentence seems mostly fine, but for some reason this feels slightly more natural. I think in a live conversation I probably wouldn't have noticed any unnaturalness.
"I would never have thought that it was even possible for me to talk with somebody who is not from the American continent but I did it." might be okay too. Replacing "were" with "was."