iIt's my second time to writing a post.

I read the last corrections, and I'm triying to be better this time.

Today I will practice my eEnglish here other timeagain (My life is boring, I know).

I'm triying to be constaistent.

I may write here every day, but I don't promise nothing.

iOPTION A: It's my second time to writinge a post.¶
OPTION B: This is my second time to write here.

OPTION B is more natural than OPTION A, although both are possible.

OPTION A: I read the last corrections and I am triying to do better this time.¶
OPTION B: I read the previous corrections and am trying to do better this time.

Today I practice my english here other time[MEANING UNKNOWN / 含义未知 / SIGNIFICADO DESCONOCIDO / 意味不明] (My life is boring, I know).)

I triOPTION A: I am trying to be constant.¶
OPTION B: I am trying to bemake a constant effort.

OPTION B is more natural than OPTION A.

I may write here every day but I don't promise noanything.

My Second Post

Saying just “second” can sound odd, you need to specify what this second thing is. Since you’re referring to writing on here, you can use words like “post”or “entry”, you should also specify that it is YOUR post/entry

it'This is my second time to writing a poston here.

What you wrote was fine (minus the “to” since it’s unnecessary), you just need to change some words to make it sound more natural

I read the last corrections and I’m triying to be better this timuse them to improve.

I’ve always heard the phrase “I’m trying to be better” used as saying you’re trying to change as a person, I’m not sure how others would see it, but I’d recommend replacing that with something else like saying you’re trying to improve your skills

Today, I’m practiceing my english here other timeagain (My life is boring, I know).

This was a bit hard to understand, but I think I got it.
1. You should say “I am practicing” (and you can say “I’m” as it’s a contraction of “I” and “am”) since you are currently practicing your English
2. “Other time” is normally said when referring to the future.
Ex: “We can do this another time.”
The word you should use here instead is “again”
I’m not sure what that last part is referring to, it seems very out of nowhere, so I’d recommend removing it

I’m triying to be constaistent.

You used the wrong word here. “Constant” something is happening non stop, “consistent” means that something is happening often at a similar pace each time

I may write here every day, but I doncan’t promise noanything.

“But I can’t promise nothing” is grammatically incorrect, but I’ve heard native speakers say it, it’s either a dialect or very very informal speech, I’m not sure