I had the good fortune of attending a university that used the APA style guide, which gave me the opportunity to break free from the horrible MLA format that I learned in high school. So, no double space after a period for me, despite my advanced age.
Note: I understand that this is a typewriter thing, but while I had occasion to use a typewriter as a kid and teen, they were mostly no longer relevant already and I was never really taught anything directly related to typewriter typing. It is ridiculous that MLA stuck with that rule for so long (I don't know if they have dropped it since).