The problem with
that design is you HAVE TO use the half inch ratchet, and then there is nothing you can do to firmly secure the tool to the bb. This is particularly problematic given these tools only catch a mm or two of the splines on the bb and that tool is also over tall in my view to further encourage slipping in action and mangling the splines in the process. Instead I would recommend something that looks like
this (which is similar to the
Shimano tool for 1/3rd the price) to use with a big adjustable spanner, and which allows
the tool to be bound to the bb in action.
Square tapered bb's with hollow spindles are increasingly rare for a qr skewer to be used, but all it takes is the right bolt and a couple of washers. The crank bolt is usually too short so get a M8 x 1mm fine thread bolt and a couple of washers - b&q sells the whole lot for around 40p.
Separately since the chance of stripping the threads on an alloy crank is significant for a novice when using a crank extractor, I would suggest the OP follows the instruction very carefully - most of all do not forget to remove the cap on the tip of the crank extractor when using on a square taper.