Interested in Language
Please be aware that I'm neither a native English speaker nor a teacher.
not a teacher
If you gave me one (yes please) I would say "Thank you very much for the satchel".
The BrE translation of the website says it is a "satchel bag". "Shoulder bag" would also be an acceptable alternative in AmE.
I'd call it a messenger bag.
Shoulder bag is too generic.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.
Evidently it is cool.
In the UK, it's a messenger bag, a despatch bag or a courier bag.
I wouldn't use satchel - they are traditionally carried in the hand, not on the shoulder. However, I notice from a quick Google search that many satchels now come with a shoulder strap so perhaps the word does work.
Remember - if you don't use correct capitalisation, punctuation and spacing, anything you write will be incorrect.