I've never had any formal training, but I've taken tens of thousands of pictures. Most of them I just use my phone on, but we do have a DSLR camera too. (larger camera with interchange lenses)
To get those guinea pictures I took about 20 photos and those where the ones that came out good.
A couple of tips are...
1) try not to zoom in when using a digital camera. Digital zoom causes pixelation and degrades the image quality. I never zoom in more than 2x, ever.
2) if your camera is having trouble focusing items very close up, use something metal and shiny (a ring, nickel, etc) to hold next to the item you want a picture of. The auto focus will snap right to the metal item. When it does, remove the prop and quickly snap the picture. It takes a bit of practice, but it's how I take macro shots w/o a special lens.
3) Be ready to take 10x more photos than you plan on using. The more you take the higher the chances of that "perfect" image being there.
4) Always try to remember to delete the extra photos. Being you are using a tablet (same for phones), if the memory gets to full, it will slow down the performance of the device. That's more for the quality of life vs quality of pictures though.
No! 
