Hi nightbyfly
Welcome to the forum and good wishes for many years of flyfishing, retail therapy and overdrafts
There'll be plenty of people around to advise you more specifically about what gear you might need for the rivers of Shropshire, which rivers etc etc.
I assume that you are having a lesson from a qualified instructor or a very experienced friend. They will be able to give you lots of advice on buying tackle suited to your needs.
You're right in that there is a lot of choice out there and it can be very confusing to a beginner, let alone an experienced fisherman - hence long debates on this forum. So don't rush in to buy gear.
The good news is that amongst the recognised brands, there are not too many totally rubbish rods and you don't have to spend a fortune to get one that will get you under way and do all that you need it to.
Up to a point, the length of the rod is not the important factor except under certain conditions - e.g. a longer rod can give you more control from a boat than a shorter rod, a short rod is more useful on a small, overgrown stream.
Rods are rated according to the weight of line that they are designed to work with. The lower the rating, the lighter the line. So a 9ft 3wt rod might be what is needed on a small river, but a 9ft 6wt would be more useful on a stillwater.
Anyway, your lesson will make it all a lot clearer.
There are lots of friendly people on here and lots of good advice, so ask away
