The registration with PayPal is free, to proceed with the subscription you need to:

Access to PayPal
from the website and click on Sign Up, found in the top left corner.

Select the type of account
Select the type of account you would like to activate:
You can choose between PayPal for you and PayPal for business.
For you - The account for those who buy and sell online
Business - The account for businesses

Fill in the subscription form
Entering the requested information.

Check the email account
Where an email will be sent, with some simply instructions to confirm the activation.
Once you have confirmed the registration you can start using the PayPal account to send and receive your payments safely.