User Create Account Hide/Show Drop-downs based on User Selection Options

[aon]

Hi All,
Amateur coder here. In the create account page I want the customers and dealers to sign up through the same portal. Here I have incorporated a number of drop down menus, however I wish the dropdown menu's to only appear/hide if certain options are selected by the user.

Once the User has inputted their first & last names, email and password, they must then choose from the dropdowns. The first drop down must always be shown. Here the User must choose whether they are a (1) customer or a (2) dealer.
If they choose (1) customer, a second dropdown menu appears asking them if they are a yacht owner.
The second dropdown menu will simply have the options (3) yes or (4) no.
If (3) Yes is chosen, they are shown a third dropdown menu asking them for their HIN or Yacht's serial number.
If (4) they can just accept the T&Cs and create an account.

If the User chooses (2) Dealer, a second & third text input menu will appear at the same time. One will ask what their Legal name for their dealership is, and the other is a confirmation code - so we can check if it's actually them signing up.
The User can just accept the T&Cs and create an account.
Hopefully this isn't too overwhelming. Please let me know if there is simple code to execute this?
Thank you and Best regards!