How save myNode for using in other projects?

If I create my node, can I somehow store it in the node library for using in other projects?

yes, you can save your .vl document somewhere and reference it from another .vl document: Referencing Libraries | vvvv gamma documentation

or if you want to publish and share it with others, you can create your own package: Creating a new Library/Package/Nuget | vvvv gamma documentation

thanks!