Create a simple login and signup form in which the user should choose if he wants to login or signup at the beginning.
In which a user enters user name, id and date of birth in a binary file and checks if the id already exists it gives an error(because id can’t be duplicated) and if not it writes the name, id and age of the user in the binary file( it calculates the age of the user).
The user should enter the username and ID and if the ID exists in the file then the program should print “login successful” and displays the whole info about user, otherwise it should print “Wrong id! Try again”

I see this is your first post. Remember that most agree this is not for others to write your code for you so try again and show what you tried, and then where you think it failed.

You won't learn by having others write your code.

PS: Try to be more creative about your post title.