Understanding AFR or Practical Tuning course?

Basically asking what should be my next step, the next course on the list is Understanding AFR, but I'm wandering if it will be better to go through the Practical tuning course first.

What do you guys/girls suggest?

Thanks in advance!

The AFR first - if you don't understand why you're doing something, it won't make as much sense to you.

The next thing to do is AFR, but you have to be very clear about what you learned in EFI Tuning Fundamentals. The other courses build on this one and take all the knowledge learned for granted.