I just Started to learn HTML coding,But don't understand how to add design in code means website layout.

This is the great for tutorials.
http://www.w3schools.com/

For design use dreamweaver, it is very easy to place your design in proper coding and layout.

Dreamweaver is really very helpful for both design and coding.

Choose in menu View > Design and Code, option. thus you can navigate both options for design and coding.

Thanks

i think you'd better read one or two books about html and css first

it's simple language, easy to learn.