Not mixing it. You have 2 choices.
1. Sit down and write an entire page out in php and add the necessary items to your SQL DB
2. Use the page builder to build a custom page with all the entries that you want in it.
Your issue is that you will need to define where the data inputted by your user goes so you'll need to create a second page that you can access or the initial page you create will generate an email form.
Take a look at the contact us page in the site and maybe see how you can modify & rename it to achieve your end goal.
***Edit: There is 1 other solution for you, you can locate a coder to create the files you need, upload them to your server and write a sql injection to create the correct DB entires.