Adding a Line need help

I recently purchased a sim kit and i thought i had purchase an activation process, because I was being guided by an agent. However on the receipt after realizing my ellipsis jetpack never activated. The receipt said that i had purchased a number transfer. Now thinking back, I asked him why my jetpack needed a number but he never answered me. Simply did a smile face ":) Yes Please." and told me that adding a line requires a new number. But when he was guiding me he was being very vague with questions I asked. After purchasing it. It said that my auto pay is now 230 bucks so did i add a new line or what? Im so confused