Affinity photo is fully available for ipad
it's $20, but it's basically a full photoshop alternative for ipad. I have it for PC and it's fantastic.
Photographers usually have a lights to highlight the subject better. Sometimes a ring light or something like this: https://www.amazon.com/Photography-Professional-Continuous-Equipment-Reflectors/dp/B08JM41FHT
I'm a hobbyist as well so I don't have that yet. So for my portrait I'm sitting in front of my window around 4pm for correct lighting. I position my camera on a chair and sit on the floor. If I focus correctly it wont be visible that I'm sitting on the floor haha. It can also be fixed by giving the background a blur in Photoshop (or shoot with bokeh).
Sometimes you have to be creative and use everything you have :)
Maybe using a tripod and only uses the lights for accent lighting will make more sense.
You may also have to resort to panorama stitching. And with murals, if you move the camera, you'll need specialty stitching software. Most panorama stitching packages assume you're rotating the camera, not moving it.
If you do stitch panos, I'd recommend learning perspective correction as well. With Hugin, it can be as easy as dragging around in the GL preview before you stitch (use the Move/Drag tab. Dragging horizontally changes yaw, dragging vertically changes pitch, right-dragging changes roll).