When u join up with dalmelington get a form for a SACU trials registration card this will allow u to do any national event. All closed to club trials u will have to join there club if u want to ride there trials.
Also consider east neuk wobblers and the lothians trials club, they are AMCA clubs and mainly cater for newbies and twinshocks,
http://www.lothiantrialsclub.co.uk
http://eastneukwobblers.webeden.co.uk
Good luck