I have decided to buy Nikon D3200 18-105mm VR Lens camera, finally! My question is would I be able to shoot insects and photos with great resolution? Distance is not a problem, I can go close to the subject.
You can make non-macro (micro in Nikon lingo) lenses focus at closer distances, and at higher magnification, using extension tubes.
Extension tubes add additional distance between the lens and sensor and have the following downsides:
Loss of light; anywhere from 1-3 (or more) stops of light loss depending on the amount of extension
Inability to focus at infinity; meaning when the lens focus ring is set to infinity, it won't really be at infinity, but this is usually not a factor when doing macro closeup work
You must get the lens physically closer to the subject than you would if using a true macro lens
If you want to retain autofocus and exposure (i.e. aperture) control, then get tubes either from the manufacturer, or, I suggest Kenko brand which offer these features. You will most likely not have one, or both, of these abilities with cheap alternative tubes.
To shoot insects and close-up of flowers you need a macro lens. Nikon calls them Micro and makes several of them.
This camera requires a lens with a built-in focus motor to autofocus, so unless you plan on focusing manually, you need to look for an AF-S Micro lens Or the equivalent third-party model. For insects and to avoid having your shadow over the subject, it is recommended a medium to long focal-length, something like the Nikkor Micro AF-S 85mm F/3.5G DX.