On top of what’s been said: People will suddenly spawn right next to you and start talking, seemingly mid-sentence. Your thoughts will be interrupted, errors will increase, and on top of all that, they expect the right response.

It’s hell, at least for me. Try it if you want.

This is just my experience. Every workplace is a bit different, but I think my answers will be generally applicable.

• Are people going to be annoyed at me if I fidget, move around, and pace a lot? Yes

• Are people going to be like, constantly looking at my screen? Am I going to feel judged the whole time Yes
• I have the classic ADHD “do double the work in half the time, do nothing the other half”. Am I going to be judged on my work output, or how busy I make myself look?
  Busy work is going to be the most important aspect of your time. Looking busy without being busy is an important art
• If I have downtime, would it be acceptable to read a book or something?
  No
• If I have a chat with my coworker sitting next to me, is the whole office going to hear it? Am I going to be interrupting and bothering everyone? Everyone will hear and short conversations are often considered fine
• Did you disclose ADHD to your boss? Did you get any accommodations for it? Not ADHD but anxiety and depression. They don’t really care. Make sure you do the paperwork for FMLA to cover your ass if behaviors become disruptive in your environment

So a lot of this is going to be difficult to answer as it depends on the work culture and individual personalities of coworkers.

• Fidgeting is generally fine as long as it’s not noisy fidgeting. If it’s something like pen clicking, that is more likely to bother someone. Passing depends on the layout. If there is decent space you should be fine, but if it pushes you really close to other people it may make people uncomfortable.
• People will almost certainly see your screen, whether they care what is on it is pretty dependent. If them seeing it makes you uncomfortable, some offices allow the addition of privacy screens which may help and is worth asking about if it will improve your quality of life.
• Some places make a big deal of always looking like you’re on task while others just care about output.
• Downtime is pretty much the same as the previous answer. Depends on your management and work culture. Might be an easier sell if your reading somehow relates to your work.
• People will be able to hear, but talking is generally acceptable at a reasonable volume. Just be considerate of those around you and don’t distract people if they are busy. Along this same lines, you’ll also hear other people’s conversations. That’s why I wear my loop earplugs age have headphones for music. Helps me focus when I need to.
• I did not disclose my ADHD, but also didn’t request any accommodations since I can have my earplugs and headphones which is really the only thing I needed. I’d love to have an office so I could close people out when I was especially busy, but that doesn’t really fall under reasonable accommodations.

My experience is pretty good as the team has the general mindset of, “Avoid waisting other people’s time, get stuff done, and do quality work. If you are doing that we don’t care what your process is.”

A lot of movement is going to draw people’s attention. It’s just baked into humans. If you need to do movement that is going to be in people’s line of sight while they work, just go for a walk.

You will feel watched and judged. But the reality is they have their own work and problems to worry about. Generally if your not interfering with them doing their own thing, they don’t care.

People being OK with you doing off task things like reading would be like an earned privilege if allowed at all. You are new and will need to prove that you can deliver. If you earn a reputation for consistent, quality, on time work you manager will be more open to you managing your own schedule.

Volume control is important. Most conversations seem to happen at the level between normal conversation and whispering. This generally means conversations are not disruptive to people nearby. But always assume everyone around you can hear everything you say and choose topics/words accordingly.

I didn’t share my ADHD with my manager until I was well established in my role and trusted that wanted to help me succeed. I’m not saying that is the correct choice, just what I did. Before that we did have many conversations about how I can work most effectively finding the balance of what I need and what the team needs.

As for accomodations, I would get explicit permission to were noise blocking headphones and a desk that doesn’t face an area with a lot of traffic. People moving in your line of sight all day is super distracting.