Two users connecting at the same time to a remote computer counts as two connections. With the free version installed on the remote computer you and your friend will not be able to connect at the same time, only separately. The free version allows one connection, so if you want two connections or more to the remote computer being, try Enterprise Desktop.
How do I share my desktop with another user if I have the free version installed?
https://www.nomachine.com/AR10K00703