CNC is a quite big topic, especially the CAD and CAM aspects. There are a lot of materials you can look at on the internet.
For the Carvera machine, we will provide a detailed instruction manual and example guide for new users to get familiar with.
We are making step-by-step video tutorials on our YouTube channel.
By joining our discussion group on Facebook or Discord, you can meet thousands of Carvera owners and fans and get help and inspiration from each other.
Furthermore, we are building a dedicated forum and wiki knowledge base for more technical topics and detailed information.

Just go through the instruction manual and follow the step-by-step example guide to finishing the initial projects, you could learn how to use the Carvera quite easily.

Carvera supports mainstream CAM Software, and we are continuously adding new CAM software profiles based on our customers' needs.
We recommend 2 CAM solutions at this stage: Fusion 360 & VCarve Desktop.
Fusion 360 is suitable for mechanical/electronic/robot/drone parts and VCarve is suitable for woodworking, jewelry making, art making, etc. Using its 2D toolpath, you can also make PCBs.
We are also developing our own CAM software and can hopefully introduce it soon.

We have developed an intuitive PCB(Gerber format) file to CAD(DXF format) file converter for you to work with VCarve Desktop or other CAM software you are already familiar with. Then use simple 2D tool paths to mill your PCB.

If you machine steel occasionally and don't care too much about the time, then the answer is Yes! With a relatively low speed, you can get carbon steel and stainless steel milled with a clean finish.
Here is a test video on YouTube, check it out: https://youtu.be/VTWt6elB6eg

The Carvera comes with a 1/8-inch collet and a bunch of free 1/8-inch milling bits. In our experience, 1/8-inch milling bits are the most common bits used for small desktop CNCs, and can handle almost all jobs.
But in case you are rough milling soft materials such as wood, foam, epoxy, etc, you can absolutely use bigger shaft diameter ones. We offer optional ¼in, 6mm, and 4mm spindle collets for your to purchase.
Note that to adapt our auto tool changer mechanism, you can not use bits with a head diameter bigger than ¼in.

If you are a seasoned CNC user and know exactly what kind of milling bits you need for your projects, then you can prepare your own. But if you are new to CNC, we suggest using the milling bits we provide for the example projects and other initial projects. Then get new ones based on your later needs.