I would recommend a tincture or vape product in a CBD:THC ratio of 1:1 for the most "powerful" CBD effect for sleep; however, if you have never used cannabis before I would start with a CBD:THC ratio of 2:1 or 4:1 which would give you a slightly less "high" effect as you increase the CBDs. In addition, you can always look for products that have terpenes such as Myrcene and Linalool for added sleep "power".
drb