I did not understand what was needed to increase my rating. Explain, please.
What do you mean with "rating"? your account rank?
Just keep posting, then your rank will increase once it reaches certain numbers of activities.
No need to worry about merit, there is no merit system here.
Just look at the number of activity that you must achieve below :
0 activity = Newbie
1-4 activity = 1st step
5-40 activity = Baby Steps
46-130 activity = Jr. Member
136-300 activity = Full Member
312 activity = Sr. Member
700 activity = Hero Member
1200 activity = Legend
5000-6000 activity = Mythical