Hi @RachelLight,
This is going to be tough for members of the Instructure Community to answer with any certainty. "Online" instruction can have various meanings for different institutions (and sometimes even multiple meanings at the same institution).
For my institution, just saying "Online" with no other details or terminology would imply an asynchronous course (content would be delivered via Canvas in the form of videos, files, pages, links to other websites, etc, but there would be no set "meetings" where you had to be online... You'd just watch videos, read material, etc when you're able from anywhere with an internet connection. Even though there isn't a meeting schedule, there are usually some sort of loose schedule for when you should do things, maybe weekly for example, so you couldn't just do the entire course in the first week or do nothing at all for a month.
Your specific message does mention field placement, which would likely be in person, and proctored assignments (which could be in-person or online proctoring).
I'd recommend reaching out to your advisor to see if they have any more info they can provide. They may need to get in touch with your instructor for more specific info, but that shouldn't be too big of a hassle for them.
I hope this info helps a bit, even though it's not an exact answer. It's about the best guess I can give you.
-Chris