The main thing to keep in mind is that even though you are quoting someone else, it is you who is writing this sentence and this essay. You have the same responsibility to make it readable as any sentence that you write.
And I suggest you block quote. Why mash everything together? If you are working in a word processor it likely has a blockquote style, just like this little text box I’m currently typing into. You might think of a quote as equivalent to a photo (it’s like a photo of the text from the book) that deserves to be in its own separate block.
An em dash is also a very readable and very common way to separate the quote from the author of the quotation. If you are cutting a sentence short in the quotation, then put in an ellipsis. Learn to type these characters in your writing tool (as well as real quotes) either by using text substitutions (e.g. you type three periods and an ellipsis is put in for you) or learning the key shortcuts (e.g. you type Option+semi-colon to insert an ellipsis.)
If that is a page number, I suggest you say so.
Also, you might want to include the title of the book, especially if it has not been mentioned already on that page of your essay.
So you might replace this:
Jake is in love with Kate. "Jake looked at Kate and his heart began to race..." (Johnson 102)
… with this:
Jake is in love with Kate.
“Jake looked at Kate and his heart began to race …” — Johnson, page 102 “The Title of the Book”