Hi @joashenrique ,
It is very easy to add the password fields on the registration form so the user can set the password at the time of registration.
Just go to LoginPress -> Settings -> Custom Password Fields, Enable this option and save. ( https://d.pr/i/rWkcw7 )
You will see the custom password fields on the registration form.
Here is a helping documentation to understand the setting a little better Helping Documentation
Let me know if that works for you.