Attracting users in my web page using forms and using it

Hello!
I want to create a new web page that can attract any visitor. Can you tell me what is form? What are the benefits of using it? What the form elements and its attributes that we can use? Can you show me how to implement the form in a web page in HTML/HTML5? Can you show me also how to insert caption? Show me how to change the value and or set value. Can I do the same process in hiding passwords in my forms? Your answer will be much appreciated!
Thank you!
