I use a Canon DSLR (70D) with a flip screen that can rotate towards the front of the camera and an additional Canon point and shoot camera (G7Xii) that features the same flip-around screen. This allows me to see myself as I’m filming, and if need be, I can adjust everything from the screens.
Look into your camera’s capabilities. Many DSLR’s and camcorders can be tethered to a laptop with a USB cable so that everything displays on the laptop screen, allowing you to adjust focus and other settings as needed.
Otherwise, it’s just gonna be trial and error, unfortunately.