I'm glad I came across this, as I want to grow in my ranks on here, and I've been contemplating how to earn merits or buy a Copper membership and how. So I'm glad I found this, let me make a step. Good luck to Me.
Copper Membership only give the perks of a Member ranked user so you can have a clickable link in your signature and can upload images apart from that your merits column will remain the same and you can rank up only if you meet the required criteria of activity and merits.
As mentioned about if you're intention is to rankup then be active, read more, gain knowledge, contribute to the forum in some way then sooner or later you will see merits awarded for your posts.