Use woocommerce with calculated quot from front end
<p><br>
I'm developing a website for a courier service, that has service quotation filling at the front end. <br>
I did all form things working, a quotation will output variable with the cost of service in PHP.<br><br>
After filling the form there will be checkout button, with that checkout button i need to save the details of the user, and that price to the woo commerce page to check-out/or fill further details.<br><br> I searched throughout the google and got 1 solution to create a product with these values in front end. But its became very difficult to figuring out signing in, saving values, keep details in specific formate etc... for me as a beginner in PHP.<br>
Can anyone help me with this?.<br><br>
i just need woo commerce to make checkout with user entered details in the form.... <br>. </p>

<p><strong>EDIT &amp; Updated :</strong><br>
Thanks for reply  LoicTheAztec, I have gone through quick toure now<br><br> 
<strong>About code</strong> : I'm sending the values calculated in form to the page called buy-now using URL using javascript <code>window.location.href=</code>.<br>
like <code>http://example.com/buy-now?price=120&amp;weight=80&amp;location=000001</code><br>
And also I'm able to fetch the value using <br>
<code>if (isset($wp_query-&gt;query_vars['pricef']))</code><br> in page template. (with StackOverflow help) and I'm checking user is logged in? using <br><code>if(!is_user_logged_in())</code> <br>and showing login form, After login also i can get the variables.<br><br>
Now I need to create a transaction using this. 
Saving data like a product or post and proceed for payment, I don't need to use woocommerce to do this but need some sort of idea to make it work. <br>
 Thank you.</p>