Hi guys, how’s it's going?

Just a side note that this is very informal language, mainly because here “it” isn’t referring to one specific thing, but rather things, or life, in general (it’s perfectly fine for conversation though, just wanted to point that out)

“Hi everyone, how are things going” would be more formal

I need some suggestions about the app called, Duolingo.

“Called” isn’t completely necessary here, but still ok to use

I'm learning a lot of eEnglish with this website; however, it's impossible to post everyday/difficult to post a text with good content every day (Could I have said plot instead of content?).

Remember to capitalise English because it’s a language.
You should have a semicolon before “however” to separate the two clauses more (or otherwise you can just cut the sentence into two parts and start the second with “however”)
I suggested “difficult” as more of a technicality, because technically it’s not entirely impossible but it’s perfectly fine to use it to emphasise the difficulty of the task.
I think generally (if not all the time), with “post”, you would follow it immediately with what you’re posting (“a text with good content”), and specify the time later on.
I’d also probably stick with “content” unless you usually write stories or something creative, in which case “plot” would work well.

So, many people ion this page talk a lot about Duolingo, i. Is it worth to use it?

Using a comma after “so” in this situation makes it a conjunction, so here it would be like you were saying that people talk about Duolingo to help with thinking of ideas to write about (but I doubt that’s the case for most people). Without the comma, “so” emphasises the amount of people talking about Duolingo.
You need a conjunction or some way to connect the two clauses together, or otherwise start a new sentence (like I’ve suggested), because it sounds unnatural to only have a comma.
You could either say “is it worth using it” or I think “is it worth it to use it” could be grammatically correct, but the repetition of “it” makes it sound bad, so “is it worth it” would sound better.

You could also say “so many people on this page talk a lot about Duolingo, so I was wondering if it was worth using it”.

I don't know how it works but it shouldn't be reallytoo difficult.

I prefer how this sounds

I'm certain that finally, if I liked using Duolingo, I wouldn't stop using Langcorrect.

I think starting it with “in conclusion…” or “to summarise…” would be better than “finally”, but it doesn’t really work here because it’s not really concluding or summarising your text.

Do you learn more (by) using LangcCorrect or Duolingo?

“By” is optional

I'm learning a lot of english with this website however, it's imposible to post everyday a text with good content everyday.(Could I have said plot instead of content?).

I think content is better in my opinion.

I'm certain that finally, if I liked using Duolingo, I wouldn't stop using Langcorrect.

Hi guyseveryone, how it's going?

Replaced guys with everyone for more gender-inclusive language.

I'm learning a lot of eEnglish with this website h. However, it's impossible to post here every day a text with good content(quality text. Could I have said plot instead of content?).

You can say content for a more general answer.

Sometimes, I have no idea what to write about.

You can look at the writing prompts tab on LangCorrect to see what you can write about.

So, mMany people in this paghere talk a lot about Duolingo, i. Is it worth to useusing it?

I personally use it as a language learning supplement, but I don't use it to learn Spanish, which is one of the most developed courses on Duolingo. However, I use it to learn Norwegian as a beginner and to learn additional vocabulary and phrases in German.

I don't know how it works, but it shouldn't be reallytoo difficult.

I'm certain that finally, if I liked using Duolingo, I wouldn't stop using LangcCorrect.

Do you learn moreinto using LangcCorrect or Duolingo more?

These days, I love using LangCorrect because it's more helpful learning all the languages that I'm learning so far.

Hi gGuys, hHow’s it's going?

I need some suggestions about theadvice for an app called Duolingo.

I'm learning a lot of eEnglish with this website; however, it's impossible to post everyday a text with good content every day. (Could I have said plot instead of content?).

“plot” refers to the story for a book, play or film. As you’re writing a journal entry, “content” is the correct word.

So, many people ion this page talk a lot about Duolingo, i. Is it worth it to use it?

“a lot” is optional. Better without it.
Or you could say, “So many people talk a lot about Duolingo on this page.”

I don't know how it works, but it shouldn't be realltoo/very difficult.

I'm certain that finally, if I liked using Duolingo, I wouldn't stop using Langcorrect.

I'm learning a lot of eEnglish with this website h. However, it's impossible to post everyday a text with good content everyday (Could I have said plot instead of content?).

Plot mostly refers to either the things that happen in a story (movie, show, book, etc.) or to describe people planning something against someone or something else.
"I loved the plot of that movie" or "They plotted to steal my dog"

So, mMany people ion this pagsite talk a lot about Duolingo, is it worth to use itusing?

I'm certain that finally, if Ieven if I ultimately liked using Duolingo, I wouldn't stop using Langcorrect.