Rio de Janeiro, the City DuDangerous. City

Wrong spelling of dangerous, order should be changed

I feel many sad for Rio.

Sadness is uncountable, so there should be no many.

I Llove my City, it's so pretty.

Only the first teller of a sentence or a proper noun should be capitalised.

But, on the last time her ie was very duangerous.

On is useless, Not her, here. We are talking about the past so it should be was very dangerous.

He is theIt looks terrible for us residents.

I don't know what you are trying to say here.

Today, I'm not going to my University, I have my class canceled for a shootout between Police and Gang members.

It is the present continuous tense, so not going is correct.

The Red command areis terrorizing the region ofor my Uuniversity.

Wrong spelling of command, Since the command is only one, it should be is, not are

The Federal University ofrom Rio de Janeiro is the most renowned federal institution most Renowded in Braszil.

Not from, of because the university is a part of Rio. The word order should be changed. Spelling of Brazil is wrong

However, we're hostages tof failing justice and politic theizing of my country.

Not howver, however. Lots of changes between words.

In the last days, an reasearcher discovered the soluction for the quadriplegia.

"Researcher" does not start with a vowel so an will not come, a will come. Not reasercher, it is researcher. Not soluction, solution.

This researcher and many others were blockeds to went from going into the labaoratory in UFRJ for theses criminals and for the failure of Justice fromin Brazil.

Many others fits better in this context. Blocked is nonfinite, so it does not change based on whether the subject is singular or plural, so it should be blocked. To went is wrong. Went is not an actual verb, it is the past form of go. And for many other reasons, from going is correct. Wrong spelling of laboratory. These is already plural so the s is useless. Not fail, failure if talking about in abstract form.

Rio de Janeiro, the City DuDangerous. City

Adjectives (dangerous) almost always come before the noun. No need for a period in the title

I feel manyso sad for Rio.

"Many" is for things that are countable

I Llove my Ccity, it's so pretty.

The words love and city shouldn't be capitalized. For emphasis, you would add more words if needed (I really love my incredible city...)

But, on the last time her lately it is very duangerous.

He is theIt looks terrible for us residents.

He and she are almost always reserved for living things that can be gendered. Objects / non-living things use "it"

Today I'm not going to my Uuniversity, I hav because my classes were canceled fordue to a shootout between Pthe police and Ggang members.

No need to capitalize university / police / gang

The Red coCommand are terrorizing the region for, including my Uuniversity.

The Federal University ofrom Rio de Janeiro is the most renowned federal institution most Renowded in Braszil.

However, we're hostages to the failed justice and politic theal systems of my country.

In the last few days, an reasearcher has discovered the soluction for thea cure for quadriplegia.

You might add a very short description of this disease since it is relatively obscure

This researcher and anothers were blockeds to went in from going to the labaoratory in UFRJ forby theses criminals, and forom the fail Jed justice fromsystem in Brazil.