Those answers depend on what type of work you do and your boss/s should let you know what you can and cannot do! Food that should be your choice!
To a point. Like I said if you work in say an eye doctor office or somewhere that you are in other people's face you should not eat onions or other stinking foods.
You are correct in only the boss can tell you what is expected. But some good work habits that are for every where -
Be on time. Actually be a few minutes early. If your shift starts at 7:00 then be there are ready to start at 7. Not sliding in to the parking lot at 7 and run thru the door clocking in right at 7 or a couple of minutes after.
Don't stay on break longer than you are suppose to. Not even a couple of minutes. A lot of places you take turns taking breaks and if you take too long you cut in to someone else's break time.
Take care of yourself. Don't worry about what other people are doing unless it directly effects you.
If you have anger issues then get some help. Being a bully will only get someone hurt. Sooner or later the bully will go to far or the victim will get fed up and react.
Don't call in/out how ever you say it. That makes it tougher on every one else. I use to work with a girl that had gotten until she called in once a week. The let her go a few weeks ago.
Don't leave early. Again, that makes it hard on every one else. Someone has to take up the slack from having to do your job.
Actually DO YOUR JOB. Don't just show up and take up space. You are getting paid to do a job so do it.
I am sure there are other things. It is mostly common sense. You are hired to do a job so show up and be on time and do that job.
I know my thoughts are in the minority because most people these days are slackers and want money for nothing. They don't want a job they just want a check.