What? No. Just no.
1. Stay away from pick up groups unless you know for sure that the organizer is competent. On bismarck, a good 90% of them are terrible.
2. Your anni's not going to do anything for you. Showing up with grossly outdated gear and what appears to be a 95 anni isn't going to make anyone competent leader happy about accepting you as a member. Luckily, you can just buy the strongest gun
Donderbuss
Once you get a bunch of up-to-date pieces, you can start offering to come RNG.
BEST route for you is to either become an epic WHM or COR. For WHM, level your SCH or...or......what the hell were you using as a sub to WHM before you took a break? I'm gonna go ahead and assume you didn't care for WHM so I'll skip over it.
Other option is to go COR. Get the AF3+2 hands and augment the AF2+2 head. Buy a Donderbuss, merit Last Stand and shoot things. You'll do terrible damage at first but it'll get better as your gear improves.
All else fails, level GEO. GEO isn't used as much these days, but you can always find room for another, given the group doesn't already have 2 who can't switch to a different job.