SimonF is spot on. If you’re trying to get 3D resolution, ball end mills are the way to go. If you’re just clearing material out, flat end mills should be used. As far as your feeds and speeds go, that’ll come with time and experience. I’ve spent a fair amount of time with scraps of whatever material I want to work on - just getting it dialed.
Regarding tool changes, Luban isn’t a good option. Honestly, Luban isn’t a good option for most SM operations. I always use Fusion 360 for my CNC paths. You can do tool changes one of two ways. Either program the tool change into the gcode, or (and this is the easier method I use) simply use one gcode file for the roughing passes, and then create another for the finishing passes. This way, you can change tools and only have to change the Z value for your work home (to adjust to the new tool).
I usually start with a 3.175mm flat end mill to remove as much material as possible. I’ll then step it down either with a ball end or a flat end - depending on if I’m going 2D or 3D. For cedar wood, I would recommend using a 4 flute corn flat end mill. It will give you a much better finish than a 2 flute. I’ve got a range from 3.175 to 0.5mm diameter bits. It’s always good to have options to step down to. Naturally, the smaller bits will take longer, but they’ll give you much better resolution.