Just point at anything, and rotate the focus wheel until the image gets clear. 

It can be used as a microscope and telescope--"See" space and design of - leaves, water drops, insects, bugs, vegetables, skin, wings, fins, feathers, dust, dirt, crystals, plastic edges, metals, ants, flies, spiders, crickets, flowers, petals, roots, pencil and pen heads, paper towels and tissue, money and coins, gears of watches working, broken glass, inner light bulb, teeth, tongue ear, hair, ...... 

No, the battery is built-in, and it is recharged via a USB-C cable. 

Please rotate the focus wheel until the image is sharp and clear. 

Yes. 

The microscope adopts a 2.0-inch color screen, which can be used for multiple viewing at the same time, clear and not blinding. 

Yes, the microscope comes with a ring LED light source to ensure that you can use it in low light conditions.