I arrive at the office at around 9:00 AM.

After reaching my workstation, I trurn on my computer to check if there's are any missed messages first.

You can also say, "... to check if I missed any messages first."

At around 11:30AM, I go out of our office building to have lunch.

Before 7:00PM, I go back to my workstation to finish today's work, it might go on until 8:00 PM or 9:00 PM.

This is my office routine, would you please share yours towith me? ^_^

For the verb share- you share "to" a website or social media, and share "with" a person.

I arrive at the/my office at around 9:00 AM.

After reaching my workstation, first I trurn on my computer to check if there's missedany new message firsts or emails.

If you're checking your email, it's good to write "email" here. But if you want to be inclusive for messages on another application (e.g., Teams, Slack), you can write this.

Then I make myself a cup of coffee bought from Sam's Club, it's sort ofrather delicious.

No need for "bought" as it's implied with "from" already. To soften the fairly strong word "delicious," you can use "rather"

After that, sipping the coffee, I prepare for my daily work schedule while sipping my coffee.

More natural

At around 10:00 AM, I begin my workstart working on other tasks.

I would not phrase it this way, because technically you began your work an hour ago. But I think you mean getting into specific tasks as part of your job, so I offer this alternative.

At around 11:30 AM, I go out of ourleave the office building to have lunch.

This is a bit more concise

Before 7:00 PM, I go back to my workstation to finish tohe day's work, itwhich might go on until 8:00 PM or 9:00 PM.

No need to say "PM" twice at the end. You can also skip the :00 and just write 7 PM / 8 PM/ 9 PM here

This is my office routine, w. Would you please share yours towith me? ^_^

After reaching my work station, I trurn on my computer to check if there's are any missed message first.

Then I make myself a cup of coffee bought from Sam's Club, i. It's sort of delicious.

I would split this into two separate sentences.

After that, sippingWhile I sip the coffee, I prepare for my daily work schedule.

At around 11:30 AM, I go out ofleave our office building to have lunch.

We have more than two hours ofor our lunch break, so I usually take a nap or browse some stuff in my car after my lunch.

At around 5:30 PM, it's time for dinner.

Adding this for consistency.

Before 7:00 PM, I go back to my workstation to finish today's work, itwhich might go ontake until 8:00 PM or 9:00 PM to finish.

This is my office routine, would you please share yours towith me? ^_^

After reaching my workstation, I trurn on my computer to check if there's are any missed messages first.

Then I make myself a cup of coffee bought from Sam's Club, it's sort of delicious.

Grammar is okay, but "sort of delicious" is a weird way to phrase it (unless you're purposely being funny). Maybe you want to say something like, "It tastes okay" or "It's good enough."

At around 11:30AM, I go out of our office building to have lunch.