There's really nothing to do differently - just know that getting a cold will make you more achy that the average person and it may last longer for you than for non-RA folks.
When I was first diagnosed, one of my first questions was, "Should I be working with 700 bundles of germs every day?" I am the tech director in an elementary school. My doctor said that wouldn't be a problem, and so far, it hasn't.
In 2011, I experienced being hospitalized with sepsis because my body couldn't fight an infection. I'm told I was very close to death. That's a danger we all face with RA and it changed me both physically and emotionally. But knowing that I did survive makes the next time a little scary.

Suppressed immune systems caused by meds will bring on infections. So for antibiotics to work, you need to stop said meds.

Nothing to do differently. The best thing you can do is take mega vitamins & try to stay away from anyone who has a cold or flu.

Just treat it like you usually do, notify dr. if you get short of breath or unusual cough or something that concerns you. Your meds are supposed to help your body handle problems normally. Just beware of secondary infections, sinus, lung kinda stuff.

I've been lucky not to get sick more often with a compromised immune system due to RA. I might wash and purell my hands a little more though! Otherwise I've treated a cold just like I did before RA.