That is going to depend on what you are teaching and how many course you are teaching; also, are you teaching remotely or on-campus or even a combination of both? That is not unusual in this day and age...
You will need to prepare lesson plans for the next class session, grade papers from the last session, be sure you are up-to-date on the latest news in your field, have articles ready to share and discuss with the class, have a back-up plan if the power goes out, the computer wipes out your work, half the class has the flu and doesn't show up, the videos don't work, or the Hand of God comes smiting (ok, you really can't prepare for that last one - but the others - be ready for the unexpected - it WILL happen!)
You should already have a basic idea of each class session before the semester starts - depending on your College you may have created the lesson plan, or you may be using someone else's - regardless, you WILL end up tweaking it before each session to reflect what was or was not accomplished in the last session and to delve deeper into topics that are pertinent, timely, and fresh. You want to keep the class entertaining and not have students reading slides - engage them.
Grading paperwork will take the longest of everything you do. You also need to ensue that students are not plagiarizing other's work. Most Universities now utilize an automatic program to upload documents that will scan the entire paper and check for plagiarism, but you ultimately have to go back and look it over to decide if it was deliberate or just an honest error in citing. You also need to ensure the paperwork is done in accordance with the standard you set in the syllabus and that matches that University's grading scale and system.
Basically - it is a full-time job for part-time pay ;o)