for you to reach the rank of a Jr.member as i do right now, you should at least have 30 Activity done using your profile thru posting or replying on other topics posted by different users. but as of the new update, Merit are also now included on as one of the basis on the ranking system to avoid Spammers who keep posting Nonconstructive topics and who's clearly just trying to raise their rank immediately.

Also try to visit some Pinned post on this forum.
here's a the link: https://bitcointalk.org/index.php?topic=1689727.0
this Post was created for beginners guide so they don't need to bother posting questions that has answer already. make reading a habit cause it's a good way to start and help for you to post Constructive topics which could also help other beginners to start their journey in here and by that you might earn some merit soon.

hope i was able to answer your question.