I don't know how you got some of the symbols that are evident in place of quotation marks. Also, a new paragraph can be indicated by skipping a line. My internal comments will be in caps for contrast.
How was Brutus considered as "the noblest Roman" despite the fact that he was one of the conspirators?
Julius Caesar, written by William Shakespeare in 1599, was one of the most successful plays in our history. Although it is called Julius Caesar, the story is more focused on so-called man (COMMA) Brutus. Brutus was a very good friend of Caesar who (DOES "WHO" RREFER TO CAESAR OR BRUTUS? BETTER IF "BRUTUS, A GOOD FRIEND OF CAESAR, JOINED....") joins the conspiracy against Caesar and end(S) up killing him. Although he was one of the conspirators, he was considered as "the noblest Roman" from ("BY") his enemy. The reason for this cause was Brutus ("HAD") different reasons of ("FOR") joining the conspiracy to ("THAN") the others, the way he joined the conspiracy and his noble acts shown to the others. (THIS LAST PHRASE IS AWKWARD. TRY A NEW SENTENCE.)
Unlike the other conspirators, Brutus joined the conspiracy because he was afraid of Caesar being strong and thought he might end up being a dictator. The other conspirators (COMMA) however, decided to kill Caesar because they were envious of his power and was ("WERE" PLURAL NOUN, "THEY") money-hungry. Brutus killed Caesar because he loved Rome more than him (COMMA) and he was dedicated to bring peace in Rome with ("AT") any cost. He wasn't sure whether he should join the assassination plan (COMMA) but after realizing that Caesar was going to be a ruler of Rome, he decided to join the conspiracy. Although he ended up killing Caesar, Brutus had different reasons of killing Caesar than the other conspirators.
Secondly, he was more of (DELETE "MORE OF" FOR CONCISENESS.) forced to join the conspiracy rather than coming with his own decision. He was "tricked" rather than "AGRREING WITH" to Cassius (COMMA) when he (WHO? UNCLEAR REFERENT.) sent a false letter disguised as a Roman worried about Caesar being too strong and ambitious. Being (DELETE "BEING.") convinced by this letter, Brutus decided to join Cassius and his other conspirators to save Rome from Caesar. He also thought that all other members of the conspiracy had the same mind as him, killing Caesar for Rome (COMMA) not for their own deeds. However, he thought wrong and he didn't know the truth forever. (CLEARER IF "...HE WAS MISTAKEN AND NEVER KNEW THE TRUTH.") For Brutus loved Rome more than Caesar, he had to join the conspirators in a good reason. (AGAIN AWKWARD PHRASING.)
Last but not least, Brutus maintained his noble characteristics throughout the play. When other conspirators considered Antony as a threat and plans (PAST TENSE NEEDS TO BE CONTINUED.) to kill him as well, Brutus persuades (PAST HERE TOO) them not to kill Antony as he is not a threat and he is one of the most noble and important person in Rome. (SPLIT INTO TWO SENTENCES.) He also gave Antony an opportunity to speak a funeral oration, although it was a bad decision. He accepted his mistake and also him being defeated ("HIS DEFEAT") by Antony and Octavius. At the end of the play, Brutus dies with ('AT") his own hands courageously, in comparison to Cassius, who asks help of his servant to kill him. When Antony and Octavius discovers of Brutus¡¯ death, they mourned him as "the noblest Roman" and adds that they should bury him in the most honorable way. Brutus is remembered as an honorable man (COMMA) even though he was a conspirator.
Julius Caesar is a tragic play, well describing the ambition and competition over power during the old times. It can be said that Brutus was an unfortunate hero rather than an evil traitor. Although he became one of the conspirators against Caesar, he did it for the Romans' future (COMMA) yet he still had he noble mind towards the others. Because of his love towards Rome and his motivation, Brutus was remembered as "the noblest Roman."
To get quotation marks, use the key just to the left of the "enter/return" key along with the "shift" key. For apostrophes, use the same key without the "shift."
You seem to have problems with commas, unclear pronoun referents and the correct prepositions, along with sentence structure.
Here are sources for commas and pronouns:
I don't know sources for the other problems.
In the future, if nobody is available to proofread your work, you can do this yourself. After writing your material, put it aside for a day — at least several hours. (This breaks mental sets you might have that keep you from noticing problems.) Then read it aloud as if you were reading someone else's work. (Reading aloud slows down your reading, so you are less likely to skip over problems.)
If your reading goes smoothly, that is fine. However, wherever you "stumble" in your reading, other persons are likely to have a problem in reading your material. Those "stumbles" indicate areas that need revising.
Once you have made your revisions, repeat the process above. Good papers often require many drafts.
I hope this helps. Thanks for asking.