I see that you are a newbie, so it will be pretty hard for you to do the signature campaign, at first you need to be helpful for the community, for that you will receive merit and for merit, you get higher rank and you will be able to participate in signature campaigns. Or if you have good social media profiles, you can start with them, it is similar to airdrops 
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.Read bro, doing some campaigns does not necessarily require a higher rank account or need a merit to do so, a newbie account can apply for almost all the campaigns in a bounty except signature, doing bounty does not end in signature campaign, op is already a freelancer and very well aware of the crypto space, am sure he can find his way around the forum pretty quick and join any campaign his account is qualified for.