If there is just no avoiding it you must never, ever forget that there is at least one gun in play.

Learn how to fight smart. Stay on your feet and stay conscious.

Some of the things you can get away with in the gym will get you killed when there is a gun or knife involved.

Practice for when things really go sideways. Find some guys and start rolling in your CCW gear. Try to access the gun mid-fight. Try to keep your opponent from accessing your gun. Learn how to make enough space to disengage safely.

Seek additional training. BJJ or MMA is great but something that includes the use of tools (guns/knives) is much, much better. If you have any friends in Group, find a guy that is a SOCP instructor. Greg Thompson knows his shit. Check out the ECQC course from Shivworks too.