you can wear any signature you want but if you're asking how will you earn some bucks while wearing signatures then i believe you're talking about signature campaigns. first thing you should know is that most of the campaigns right now is requiring such rank which is a Jr. Member. how to be a Jr.member ? you need to Post/Reply topics. technically you need to raise your activity counts to 30 but as of the new update Merit is also now included as one of the basis in ranking due to high volume of users who are just posting stuff that is sometimes doesn't have any relevance to what this forum is all about. they're the one's who are just spamming to raise their rank, for further explanation you should read some topics that was posted by other user or first read those pinned post in this forum to guide you. going back, signature campaigns are looking for some people who are good in creating constructive post. so it is much better to do some research on your own first so you could be able to post some things that has sense in a way that other users can benefit to it.

i hope i was able to help you.