As everyone else has said - the doubt is normal. My advice would be to try and strip the product into parts more & tackle them one by one.
Creating a total product end to end in one go, that's scary. Creating a user model, easy. Creating an authentication level on that model, easy. And so on. Take it one step at a time.
Creating a total product end to end in one go, that's scary. Creating a user model, easy. Creating an authentication level on that model, easy. And so on. Take it one step at a time.