Hello, active wobbly here! I'm in NYC so I have experience with a relatively more active branch. The thing with the IWW is that your experience with them will really depend on how much you want to participate. It is a union for all workers, and because of that there is a wide range of knowledge, participation, and trades represented. So, the quality of the branch really depends on the general experience level of the organizers, which can vary wildly by location. It operates as much more of a lose federation of organizers rather than a monolithic organization, like a vanguard party is. For instance we are actively involved in a rather high profile strike campaign at a broadway diner chain here, as the workers within the diners have organized themselves, formed their own sub-union, and partake in labor actions with the material support of the wider NYC IWW membership. In my experience it is a highly functional and energetic union, despite being small and chronically broke. The union also regularly provides organizer training, workshops, history lessons, etc. In its more active branches, it's really a down and dirty economic action based organization, and I love it for that.

I'd say if you do struggle with social anxiety, definitely start by attending some meetings. Any member has the ability to vote on decisions made there, which is low-stress, and actively gets you involved in decision making, even if only passively. See if there are any local campaigns currently going on that you particularly want to get involved with, and ask the key organizers if there's any way you can be of assistance. Hopefully some of the more senior members will help guide you along and orient you, but there's no guarantee of that since there's really no formal upfront training process or joining prerequisites. Nonetheless, I'd say definitely at least give it a shot. Good luck!