Hey. I do it all the time. I have a jointer and a planer but the CNC is so much easier. I just set it up once and go have a tea. Come back to a nice flat piece of wood. You don’t need to stand then and continue to adjust your depth of cut for each pass.
You can do the top of your material and the. Use the planer for the other side. Or if you don’t have one at all. Do one side. Flip it.over and do the other.
Some tips. Zero your machine from the waste board not from the material surface. That way you can choose your final Thickness and not have to measure each time.
Try to level your material on the machine. So if the board rocks, wedge some shims under the material or what I use is hot glue. That way the material is supported and level-ish/ won’t move around.
As for speeds and feeds. I run at 18k 100ipm as for depth of cut it dependant on what you have for a surfacing bit.
Hope this helps.
Happy machining.