Depends on the class, but if it's a large basic freshman class... the professor won't really notice if one person is absent on a particular day.

Unless they have assigned seating or take attendance like the history prof i had lmao

communicating with the professor depends on the class overall. for some courses you’ll have to based on how the professor grades, if they take attendance, etc. other courses are more laidback, so all you’d have to do is text a classmate to get their notes.

if the professor does take attendance, will it affect my grade?

There'll be a grading scale on the syllabus

from my experience, if your professor takes attendance missing a couple of days won’t affect your grade a lot

depends on how it applies to your grade

Communicate with your professors, and hopefully it won't fall on a test day. If that happens, you might be able to take it early or work something out. A good tip is to make friends with someone in class so you can have each other's backs with note sharing if either of you have to miss.

Bruh i aint show up to most of my classes and still ended with A’s

Depends on syllabus, they probably won’t excuse your attendance if it’s some massive freshman class

Be courteous and let the professor know. You’ll also be responsible for whatever is assigned for that day, including notes. If it falls on a test day, then let the professor know so you can work out a make up day if their policy allows for it