Quote marks
You will have a style for your quote marks in any piece of writing. This will be “double” or ‘single’. In the UK, single marks currently seem more prevalent, as do double quote marks in the US, but this isn’t something you can assume.
One thing I discourage as an editor, if it’s in my power to, is a two-tier system, where “proper quotes”, with a source, are in double marks, and ‘scare quotes’, that convey a ‘so to speak’ quality, are in single. I think this confuses the reader, who is unlikely to know the difference, and it causes problems in the edit, giving rise to many more queries as you try to ascertain that all the quoted material really is quoted, and all the scare quotes really are scare quotes. It’s an opportunity for mistakes to creep in, and none of us need that.
Remember, whichever style you are using, to toggle your quote marks when there are quotes within quotes. This is how it looks if single quote marks are the style: ‘I thought he said “Stop”, but in fact he said “I thought you said ‘Stop’”.’