All Flare networks are a fork of the Avalanche project, which runs the Ethereum Virtual Machine.
Therefore, all Ethereum contracts and tools work on Flare, Songbird and Coston.
All Flare networks are layer-1 networks, and run independently of both Avalanche and Ethereum.
You can interact with the Flare networks using wallets, block explorers and the most common blockchain development environments.
As an example, all Flare networks support NFTs and many have already been created on Songbird.
The block explorer also supports displaying NFTs.
Once you have set up your development environment, you can start with the Accessing the Network tutorials.
These are Flare's main source repositories, both on GitHub and GitLab.