Pokemon box - slew of questions/issues

I powered up my Pokémon to try to refine the results but there was no change from the refine results button. How do you know which to select among the "Add to Box" results? What is mean by the field "Pokemon Level"? the values in the HP/ATK/DEV IV fields can be changed, but where would you get those numbers?

Thanks for your help, and please write a tutorial as
1) the video is too fast
2) doesn't explain, just demonstrates and not too clearly at that.

I'd be willing to help, and also to translate (info French).

Many thanks!

Apple II/c