Dual endstops are not for beginners. They allow each side of the cnc to love idependently, and sense their endpoints to finely adjust the angle of each gantry. Without them, you just make sure you start the motors with the gantry square (usually a tape measure works well enough) and each side moves in lockstep, keeping it square through the cuts.
The 30A is needed if you’ve got a heated bed for 3D printing, not for CNC.
The step you’re missing is the CAM or computer aided machining. CAM lets you define which lines to cut and to what depth. By far, this is the hardest thing to learn about CNC. Look for videos on EstlCAM, which is the simplest CAM to use. You’ll see how it works.
Fair warning here, this is not like your hp printer or your table saw. This is a significant skill set and the tool will not forgive you for some mistakes. This kit is built to be a good combination of inexpensive, flexibility, and performance. Ease of use is probably not it’s biggest strength, although Ryan’s setups and these forums do try to make this better. Some things are easier than others too. This machine is very capable, but it depends on the users abilities and patience.
I’m not trying to scare you away. We get all skill levels here. But the people that enjoy it the most have realistic expectations and enjoy the process as much as the result.