First test with 2 stage cut, a couple pretty obvious lessons learned

You guys are very helpful and I’m grateful as I guess I have a lot to learn about this.
One response here said 50 inch per minute, another said 60.
is there a rule of thumb? or is it all experimentation?

edit:

I read A guide to understanding basic Feeds and Speeds which was very good.
it said:
Here are the three possible ways to calculate chip load. You will need to know any two variables to solve the third (chip load, feed, and rpm). Typically you will know chip load and also know a RPM or a Feed that you wish to run out, and solve for the other.

If you know Feed and RPM………Feed Rate / (RPM x # of cutting edges) = Chip Load
If you know RPM and Chip load ………….RPM x # of cutting edges x chip load = Feed Rate (IPM)
If you know feed and Chip Load ………Feed Rate / (# of cutting edges x chip load) = Speed (RPM)

so I thought OK, I can calculate that, bit when I looked at the end mill I burned, so I could see what I did wrong,
the only data it comes with is:

Technical Data
Cutting Length 5/8 in
Overall Length 2 3/4 in
Onsrud Part #40-105
Best for Cutting Woods, aluminum

I looked up the part number online and could not really find a chipping rate target.
in a case like this, where you do not have a defined chipping rate, what do you do?