Wrong number
If a digit is wrong, the code won't arrive; after entering the number, check it once.
Opening a new account usually takes less than 3 minutes with the right information, and logging in later becomes easier.
First-time sign-up brings small questions, so each step is kept separate, so you can understand what to do by looking at your phone.
Many people explore everything at once; you don't need to; first open an account, then check the menus.
If your phone's browser is saved, the next login is faster; and if you have a slow network, review the information once before submitting the form.
If a digit is wrong, the code won't arrive; after entering the number, check it once.
If you use a very simple password, later trouble increases; it's better to keep it a bit strong.
Before finishing the form, check all fields to avoid starting over.