The 3 events I'm most likely to get to differ. I'd class none as places for showing off but.

One (strictly Irish tunes), you do need some experience and (although I fall far sort of this) perhaps need to understand that the main core who have played together for many years are of the 1000+ repertoire types. It is friendly but not a place for a beginner.

The other at least mostly Irish one is more "relaxed" but I wouldn't imagine more than one or two sets being played at a really slow pace in the evening.

With both these, anyone can start a tune set off as and when and others will join in with support (at least if it's something that fits the night).

The third (much closer to where I live) tends more towards a sing/tune around format with things generally moving round the room and more "anything goes".

I'd guess this one would be the one Kim C would enjoy most but really all 3 of these sessions do have their merits.