No, I'm not an English prof, but I might still be able to help you with your writing. I will sometimes put stylistic comments on your work, when I return it, but I will also make some more general comments here.
Non-sexist or Inclusive language.
Although some still regard this issue as "political," increasingly it is becoming simply a standard part of appropriate style. Remember that there was once a time when white men were addressed as "Mr. So-and-so," while men of color were addressed by their first names, as if they were children. The abandonment of that obnoxious practice was also a political transformation.
Avoid using "he" systematically as a supposedly generic pronoun referring back to "one." It no longer sounds generic; it sounds like it refers to men, rather than women. There are a number of different ways to avoid using "he" in this way. You can alternate, using "he" in one paragraph, "she" in the next. You can use the plural: "When people are hungry, they eat."
You can use the "singular 'they'" as well, which has the additional benefit of avoiding the gender binary.
Avoid using "man" and "mankind" to refer to human beings at large. This one is easy: write "humans" and "humankind."
For more detail on this theme, see my excerpts from the Amer. Philos. Assoc. website.
Semi-colons. Semi-colons are used to separate two independent clauses when they are not joined by a conjunction. Commas are used to separate independent clauses when they are joined by a coordinating conjunction. (You may "reduce" the semi-colon to a comma for short sentences, e.g., like this: "I'm hungry, I'm going to eat.")
It is usually, though not always, a bad idea to qualify a thesis, observation, or assertion with a phrase like "I think that" or "I believe." Such phrases tend to undercut the force of your assertion by suggesting that the idea is just something you believe, rather than something you're willing to argue for. There are times, of course, when it's most precise to use "I believe," as for example when you're making an observation about what you believe. (Also, it's just fine to use the first-person singular pronoun, of course only when it's relevant and appropriate. "I will argue that" is often a clear and simple way to let your reader know what you plan to do. Don't overuse such phrases, however, or you risk running afoul of tip #5 in my advice on writing philosophy papers.)
Avoid unnecessary present participles: The present participle is the form of the verb that's constructed from the verb stem with the suffix "-ing." In general, using a present participle rather than a form of the present tense of the verb makes a sentence passive. It can also make a sentence especially vulnerable to dangling participles. Now, there are good reasons to use a present participle. If you mean to emphasize that something is happening now, rather than that it happens sometimes or generally, a present participle is your ticket. For example,
"Kamala is driving to Washington" emphasizes that the action is happening now.
"Kamala drives to Washington" suggests something different, either that she habitually drives to Washington or that this is her preferred mode of transportation.
If you want to explain the meaning of a term, don't use the participle "meaning" or "being." For example, rather than write,
"Communism, meaning the public ownership of the means of production …," write
"Communism, which is the public ownership of the means of production …." Verbs other than "to be" will work here as well.
Commas and periods go within quotation marks, while most other punctuation goes outside. Ex.:
President Bush said, "Invading Iraq was a good move."
President Bush said, "Invading Iraq was a good move"; I disagree.
Split infinitives. Splitting infinitives is no longer considered impermissible. Handle infinitives as you think best, but be sure that however you use an infinitive, your meaning is clear and that you place modifiers where they most naturally go.
When citing a page number for a quoted passage, the period at the end of the sentence (or comma at the end of the clause) falls outside the quotation and after the parenthesized page number, thus:
Aristotle says, "I am a great philosopher" (p. 241).
Set off (indent one half inch from the left and right) lengthier quotations (more than three lines) from the body text. Single space them, and do not put quotation marks around the entire quotation. (Setting off of the text has the same function as quotation marks. Thus, quotation marks are redundant.)
When you use an inline quotation (so with quotation marks around the quote), and the author themself uses quotation marks in the quotation, then switch the inner quotation marks from double to single (or single to double, if you prefer single quotation marks.
Ex.: Sartre writes, "As for 'despair,' the meaning of this expression is simple." In the printed text, the word despair occurs in double quotation marks. When you quote the sentence, flip the quotation marks from double to single.
bartleby.com provides free online access to Strunk's Elements of Style (1918 edition, not the edition updated by E.B. White), The American Heritage Book of English Usage, and The Columbia Guide to Standard American English
Lauinger Library provides free access to Oxford Reference Online, which includes The Oxford Dictionary of American Usage and Style.
The best resource I've found on the Web is Dr. L. Kip Wheeler's grammar website at Carson-Newman College: http://web.cn.edu/kwheeler/resource_gram.html.