I used to really liked taking pictures, and I took. I used to take more than a 1,000 pictures a day inas a college student.

I used to travel forto takinge pictures, not only oceans but also. I took pictures of oceans and mountains.

But mythe company I work at doesn't allow to bring a cameras in the buildings due to security.

So I stopped bringtaking themy camera with me, and I was upset for a month.

Your sentence was correct, but this sounds a bit more natural.

But then, I found other hobbies such as reading books instead.

Don't need to say "instead" in this sentence. It's not wrong, but it is not required.

Nowadays, I bring the cameratake my camera with me only when I go to abroad.

I used to really liked taking pictures, and I took more than 1,000 pictures a day inas a college student.

I used to travel forto takinge pictures, of not only oceans but also mountains.

But my company doesn't allow us to bring any cameras into the buildings due to security.

Your sentence is okay, but this sounds more natural. :)

So I stopped bringing themy camera, and I was upset for a month.

Your sentence is okay, but this sounds more natural. :)

Nowadays, I only bring themy camera only when I go to abroad.

I really used to liked taking pictures, and I took. When I was a college student, I would take more than 1,000 pictures a day in a college student.

I separated this sentence into two sentences. "Liked" and "used to like" are interchangeable here, this is just a stylistic choice.
I also changed "I took" to "I would take", because the use of "would" implies a habitual action (that you do something again and again).

I used to travel forto takinge pictures, not only oceans but also of the ocean and the mountains.

ButHowever, my company doesn't allow to bring a cameras in the buildings due to security reasons.

You could also say "doesn't allow me to bring cameras" as well.

So I stopped bringing ithe camera, and I was upset for a month.

You can use the pronoun "it" here, since the camera topic was mentioned in the previous sentence.

Nowadays, I bring the camera only when I go to abroad.

If you are talking about a specific place, you can use "go to" (for example, "go to Jeju-do"). If you are talking about a non-specific place, just use "go" (for example, "go abroad").

When I was a college student, I really liked taking pictures, and. I took more than 1,000 pictures a day in a college student.

This sounds more natural in the US.

I used to travel for taking pictures,ake pictures while traveling. I photographed not only oceans but also mountains.

Alternative: I used to take pictures while traveling. I photographed not only oceans but mountains, too.

But mMy company doesn't allow to bring a cameras in the buildings due to security.

This sounds more natural in the US.

So I stopped bringing the camera, and I was upset for a month.

We don't need a comma in a sentence this short.

Nowadays, I bring the camera only when I go to abroad.

"To go abroad" is a set phrase.

I really liked taking pictures, and I took more than 1,000 pictures a day inas a college student.

You could say "in college" or "as a college student"

I used to travel forto takinge pictures, not only oceans but alsovisiting both oceans and mountains.

This sounds more natural

But my company doesn't allow me to bring a camera in the buildings due to security.

I really liked taking pictures, and I took more than 1,000 pictures a day in as a college student.

I used to travel for taking pictures, not only to the oceans but also to the mountains.

But my company doesn't allow to brbringing a cameras into the buildings due to security.

Nowadays, I bring the camera only when I go to abroad.