I just don't understand this static ip thing. Can anyone help?

My small business was recently burglarized. Besides damaging and stealing most of our inventory; the theives also took our last DVR for the surveillence camera setup. I have recently purchased a newer one off ebay; however, the instructions were vague and it's cloud-based. I'd like to have it record up to the cloud as well as be able to access it via cellular. I was told I needed a static ip address to route it through, so I added the service via comcast. Is anyone familiar with this kind of setup? I am fairly proficient in computers and I even have a little networking knowledge; this has got me stumped...I dont know where to start. Can anyone simplify this process for me or recommend a good website or you tube video? I would just hire an IT, but due to the losses we've just been hit with; It's definately not in our budget. Thanks in advance!