You should start in foam, have you cut anything else? Is the pen plotting perfect?
Start with an 1/8" bit, to get a good grasp of whats going on. I can’t give you exact numbers, I have no idea what you are using, “standard” isn’t really a thing here too many variables, bit type/material/geometry included.
<50% stepover, try not to slot cut use peel, adaptive or tricoidal instead. Plunge rate, 2-5mm/s, Rapid, <8.4mm/s. Feed Rate, hard to say, you have to do test cuts to find out, slotting will be at least half the speed of a peel or adaptive, 5-12mm/s depending on depth of cut 2-5mm?
I’m starting to slowly build up this page. This isn’t a fully assembled machine so I can’t give you a number to use, you will have to experiment, sorry.