First of all welcome back to the forum. Since you have been away from the forum for a long time, it will be challenging for you to work on a signature campaign in the beginning.  Working on a signature campaign requires a certain number of merits in the first four months which you don't currently have. Bro right now you should collect merit first. You must post good quality to collect merit. Since your account has been inactive for a long time, you should post regularly in the forum. If you give good regular time to this forum for a month then I think after a month you will get a chance to work on one of the signature campaigns.