How to clean and protect my dslr? Is it okay if I clean its lens with simple cotton cloth?

Hello… I have recently purchased my beginners dslr nikon d3300… But the problem I'm facing is its lens cleaning… I got the fingerprints over it on the first day I purchased it and cleaned it with a simple cotton cloth. Now I have got to know that this was the lens can damage… And I'm scared as hell. Please tell me is it okay If you clean it with simple cloth (cotton) ? I have cleaned it twice only… Now I'm using multifabric cloth

Number one in the list of things you can do, is protect the camera and lens from dust and moisture.

The lens needs to have a UV or clear filter on it to protect the lens from sticky fingers or damage.

Cleaning lenses is a tricky thing. You have to use special camera lens cleaner and using a soft application of lint free lens cleaning tissue.,

Your first mistake was not placing a filter on your lens, followed by touching your lens.

Other things like cotton cloths, silicone treated special tissues can do more harm than good.

Once you get your lens cleaned, put a clean UV or Clear filter on it to prevent further from moisture, dust, flying mud and other debris.

I suggest you take your camera and lens to a proper camera shop and have them do two things. 1) clean the front element of your lens and 2) sell you a filter to protect the lenses front element.

They will also have the right lens cleaning tools you will need to keep the filter clean.

I'd suggest a filter too if you tend to 'play' with your camera too much, you really shouldn't have to 'clean' your 'kit' that often unless you regularly photograph in bad weather or perhaps shoot motorsport, or dirt biking (motocross) etc where dirt gets thrown all around the place.

I recommend keeping things simple and just use a microfiber cloth, I don't recommend cleaning solutions to newbies, just breath on the lens for stubborn marks like you would do with spectacles, here's a clip from You Tube to give you an idea of how it's done: