I’ve seen some other posts about this online. Like others have said you basically just need to stay calm and respectful. I’d advise against cheering for your team, but I’ve seen others point out they’ve witnessed the away fans in their sections. One guy was doing a quiet fist clench that was noticed by those around him. Nothing happened as he wasn’t being a dick about it. My buddy and a couple of his friends went to watch Liverpool away at either Arsenal or Spurs… sat in the home section and enjoyed a match but again didn’t openly cheer.