Thanks Old trials fanatic and thanks to everyone who has replied. 
Most informative and appreciated, thank you all. 
In answer to your question Old trials fanatic, I haven't done a trial as yet but I know I want a friendly and enjoyable atmosphere and I want to enjoy my riding. 
I suspect these are the main targets for me and I equally suspect I'm going to prefer easy sections. 
Maybe I can relate this to trail riding in that I preferred a leisurely bimble with no awkward and difficult bits whereas most around me liked big challenges of 3 foot deep bogs and the like.  
I don't do fear, I'm not keen on pain and I'm not bothered about winning at all. 
I suppose I would like to improve over time. 
I enjoy a bit of bike maintenance and tinkering but I'm not a mechanic.  
I'm not concerned about a twinshock going up in value and I think I'd rather they didn't. 
And I'm taking my time before deciding.  
Thanks again everyone.