Creating a Goaloop account is free, and you may sign up for free as an individual, non-profit organization, or a business.  (There are two pages open to the public without even signing up for a Goaloop account: Top 3 (https://goaloop.com/top3) and Swing (https://goaloop.com/swing).)

The only time you incur a charge on Goaloop is if you receive funding through the platform, which is entirely optional.
If you receive funding through Goaloop, two transaction fees are withdrawn from the amount sent to you by the funder: Goaloop's transaction fee and the standard PayPal transaction fee (see Funding section for details).

If you fund a goal, the transaction fees are paid out of the funded amount before it reaches the receiver.  
(The funded amount is the receiver's gross earning from the transaction, and the gross earning minus the transaction fee is the receiver's net earning from the transaction; you may see these phrases referenced elsewhere.)