A few questions:
What do you mean by 'proper cyclist'?
What is your aim? Ie what type of cycling are you interested in? Ie track, Road, spotives, time trials? What level are you at ie categories or to be more simplistic are you a beginner,intermediate etc..and what are you dreams - regional, national,olypic/elite etc?
How do you work best- do you like to ease into stuff or are you a baptism of fire/chucked in the deep end kind of person?
What is your fitness like?
What are you strengths with your fitness etc Are you good at endurance or power/sprints etc
What type of people do you want to meet/train with?Ie is competiveness most important or do you want social aspect/friendliness etc - can help you make an informed decision about joining a club with the focus you want.
Lot of questions but these things are important to know to help answer your which club question...