When you reach 25 posts you become a Jr. member.
Here are all the titles and the amount of posts needed to reach them:
Newbie ~ 0
Jr. Member ~~ 25
Sr. Member ~~ 50
Experienced Member ~~ 100
Dedicated Member ~~~ 250
Full Member ~~~ 500
Elder Member ~~~~ 1000
Elite Member ~~~~ 1500
Hero Member ~~~~~ 2500
Legendary Member ~~~~~ 4000
As for the Floof O Meter it's a sort of karma meter so as people nuzzle you for various reasons like being helpful or contributing a lot in the community it goes up. Once you've reached 25 posts you will gain the ability to nuzzle others which will in turn increase their Floof O Meter. You can only nuzzle once a day.