No offense but Google Forms was built by 100s of engineers and developers, I am sure over 10,000 hours of coding and tons of planning.

You may want to start with something more basic, get that working and scale up. You aren't going to find a "How to make Google forms" tutorial.

You first need a list of features... eg what does you app need to do..

1. create form --1a) create form field types/rules/validation
2. save form
3. edit form
4. create form template
5. give permissions to users
6. etc

Once you have your list of requirements, start building your base objects and bring them all together. I am sure you will get help with individual pieces but what you are asking for is a massive thing