Zoom phone set up for just one line and two employees

I feel like I am about to lose my mind! I am with a very small nonprofit, just two employees. We were with Grasshopper for the past 5 years and I loved it, but the boss wants to save money. So we ported the number and purchased one license and a metered plan. I just need to figure out how to receive calls on the mobile app and absolutely cannot figure it out. I feel like every video is targeted at larger organizations with multiple lines. I have spent the past three days searching forums and YouTube videos and I cannot seem to find out how to get the phone number to ring! I can at least make outgoing calls and receive voicemail, but I cannot receive incoming calls yet. Please help if you can!