There is bottom reply on the right side, you can start making posts but unfortunately you are very very newbie even you don't know how to make reply on bitcointalk, will be better you must learn more about the rules of bitcointalk before start joint in signature campaign services and you must have much knowledge about bitcoins, altcoins and any other related with digital coins world, if you try to joint on signature campaign now, you will be rejected by the manager of signature campaign. Good luck