how do i create a form in Dream Weaver

What kind of form do you want? Since I am not sure what kind of form you want (I am thinking you are looking for just a simple form that has: name, last name, email, reason)...

But here is a resource from Adobe.
http://helpx.adobe.com/dreamweaver/kb/develop-form-dreamweaver.html

And a resource from w3schools.
http://www.w3schools.com/html/html_forms.asp

<form>
    Name: <input type="text" name="name"><br>
    Email: <input type="text" name="email">

    <input type="submit" value="Submit">
</form>

Above i wrote a simple form with 2 inputs, maybe my resources helped (you can always google more)

remember, when writing a form in html, keep your form inputs inside the form tags

Insert > Form > choose what form inputs you want

Please style margin auto to your container div.eg

#container{ margin:auto;}

and call from it from html as;

<div id=container></div>

To the guys who have answered me about forms please thank you. but i want to how to make form validation easier to me. thank you

Form validation should take place on the server side. So the answer to your question really depends on what server-side language you are using.
You can add JavaScript form validation to make your form look pretty, but if you don't have server-side validation and the user turns off JS in their browser, they will bypass your validation measures.