Usage of the GUI is fairly self explanatory, but there are some things you should take note of:
If you ever experience issues with the GUI 9 out of 10 times it is an issue related to the remote node. To learn more about what a remote node is and why it is used instead of a local node, see the help page on nodes.
Change your remote node by following this troubleshooting section if you're having syncing issues, daemon warnings, transactions stuck as pending, or any issue related to connectivity. If that does not resolve your issue contact me.
If you ever get a pop-up saying "starting local node in 10.. 9.. 8..", cancel it.
For additional information on how to use the GUI see the .pdf guide in your Monero binaries folder.