help please with steering on mad rat

[wolf]

im using tamiya wire system from a sand viper teu 101bk and servo and reciever .. just seem to have a problem going in a straight line plus my servo trim if full over to one side just to try and straighten the wheels..
im a complete newbie to this and a 41 year old begginer so any help would be good please ..

and another quick one is thier and clubs or anything in the woking area were i might get help with it ?