Acquaintances with someone with adhd and i don't really know if im supposed to treat them any differently like what even is adhd like?

Ask the person: If you do it politely, i'm inclined to think the person would be willing to talk about what it's like and if there are any things you can do to help things go well when you are together. What to expect and be patient about - if anything. They might say "no reason to do anything different". That's probably true. It can be mild or more intense at different times. It's mostly distractable & restless.

Not different: Don't feel that you have to treat them any different than anyone else. Adhd can be very difficult for your friend to manage, just like anything else can be difficult to manage. It is their responsibility to get treatment for it, so they manage their lives more effectively. Be a good friend and support them.