Which should I choose, newbie.

How does it work with the box, do you get it for a set period of time and do you top it up with products when you send it on? Looks like a good selection of stuff to try

Drop a note of interest into that thread. I believe it's a "keep for a reasonable amount of time" and pass on to the next on the list. The box got so big, it got split so there's two going around.
 
Brill! It is a light razor, so be mindful of this while shaving and keep your touch feather-light. That said, since it's your first DE you'll have no point of comparison and will not doubt find everything else too damn heavy

If you were chomping at the bit, you could bob down to Sainsbury and pick up a pack of Wilkinson Sword blades (usually in a plastic case). These are damn good! Very sharp, and so will make your feather-light strokes count.

For the first few goes, don't think it wrong to use this for the easy parts of your face and switch over to the cartridge to get around the complex bits where cuts and scratches are not a lot of fun.

Welcome to traditional shaving ...

Have a lot of fun!