I don’t bring many lunch forto work because my workplace serves lunch for employees in a corporate cafeteria.

It’s one of my favorite things about my work/job.

I teach English to children at a school.

OPTION A: My tasks really vary,; there are so many things to do.¶
OPTION B: My tasks really vary. There are so many things to do.

But I like my job at the moment.If *writing* : However, I like my job now. (If *speaking* the original is fine.)

SMOOTHER: After I getting home, I have dinner.

If *writing*: I don’t make dinner every day, but I make it when I have time.do so when time permits. [NOTE: When writing, the word "I" is minimized to sound polite. When speaking, you can use the word "I" a lot. However, written English is slightly different from spoken English.]

I watch some videos in these languages, read books or articles, and write an essays.

Of course, I don’t have time to do everything but I’m doing my best.

When I don’t feel like going to work next day, I check the upcoming lunch menu.

It really motivates me for real! :)

My dDaily rRoutine (2)

My tasks really vary,; there are so many things to do.

But I like my job at the moment.

I don't understand why you used "but" here, but I'm probably missing something. We use that when there is a contrast between things.

After I get home, I have dinner.

I don’t make dinner every day, but I make it when I have time.

Of course I don’t have time to do everything, but I’m doing my best.

Also, I like scrolling on X and instagram.

After relaxing time, I take a shower and brush my teeth.

Alternatively: "my relaxing time"

Before I go to bed, I write a diary.

I’ve been keeping a journaling, writing down what I did down every day.

I think you could technically say "keeping journaling," but it sounds a little clunky.

When I don’t feel like going to work next day, I check the lunch menu.

I don’t bring my lunch forto work because my workplace serves lunch for employees.

I teach English to children at a school.

Also I like scrolling on X and instagram.

Just to note that "scrolling on social media" has somewhat of a negative connotation.

After relaxing time, I take a shower and brush my teeth.

I’ve been keeping a journaling, writing what I did down every day.

When I don’t feel like going to work next day, I check the lunch menu.

I don’t bring my lunch forto work because my workplace serves lunch for employees.

I’ve been keeping journaling, writing what I did down every day.

I don’t bring mya lunch forto work because my workplace serves lunch for employees.

This may be nitpicky, but by saying "my lunch" there is a subtle implication that you do indeed make or buy a lunch for yourself, but then proceed not to bring it to work. "a lunch" refers more to the concept than to a physically existing lunch that is in your possession like "my lunch" does

I don’t bring my lunch forto work because my workplace serves lunch for employees.

"for work" makes sense and I can see why you'd use it, but I think it's slightly more natural to phrase it as bringing your lunch "to work"
I'd struggle to explain exactly why, though.

It’s one of my favorite things about my workjob.

Job is often used in this context.

After I get home, I have dinner.

Probably a bit of a nitpick, but a comma is required after the first clause. You could rephrase as "I have dinner after I get home" which would then not require the comma.

After dinner, I usually study English or Russian.

See above comment.

I watch some videos in these languageWhen I do so, I often do things like watching videos, readings books or articles, and write aning essays.

This sentence implies that writing an essay is something that you do every time you study English or Russian.
You can form a list like:
"When I do so, I often do things like watching videos, readings books or articles, and writing essays." to show that it something you do sometimes, but not necessarily every time.

Of course, I don’t have time to do everything but I’m doing my best.

Also, I like scrolling on X and instagram.

After relaxing time, I take a shower and brush my teeth.

Before I go to bed, I write a diary.

I’ve been keeping a journaling, writing down what I did down every day.

Alternatively, "I've been journaling"

It helps me remember what I ha've done and what I was thinking about before.

Using contractions in English is very natural.

When I don’t feel like going to work next day, I check the lunch menu.

"lunch menu" here requires an article. Since there is a specific lunch menu you're referring to, and the reader is familiar with it, you can refer to it as "the" lunch menu.