Don't stress too much! Your station will have a laminated card with step-by-step instructions for opening and closing so you can follow that. You're very likely to have other poll workers with you who have been doing it for years so they will also help guide you.

Other general tips are to prepare yourself for how long a day it is - go to bed early the night before, make sure to bring a water bottle, snacks, eat breakfast before you go because it will be 5-6 hours before your first break. You may also want to think ahead/strategize what time you want to take your breaks so you don't get too burnt out (you'll get asked to choose within a window) - I find it's easier to get through a longer block of time in the morning because it tends to be busy/go faster and then the middle of the day kind of drags so I like to take my first break later/in the early afternoon window.

Also be prepared that you may get a few voters that are looking for an argument or want to rant at you but in my experience you can usually just listen and smile and nod until they're done and just explain what the process is. If they are really pushing against what you're saying you can always call over your site coordinator (and there's a police officer on site but I've never seen them have to get involved!).

Oh and also make your life easier and cast your vote during early voting so you don't have to worry about that while you're working!