Car batteries are actually quite fragile and don’t like being dropped. It is very easy to damage the plates inside and you wouldn’t be able to tell. I’m not sure I would trust a parcel company to deliver it safely.
Just go to your local trade parts place, they all sell over the counter to non trade people and they will have handled the battery correctly.
Oh, and don’t buy one with a two year warranty- cheap batteries are a false economy. Ideally buy Bosch or Yuasa.
*Edit* I just spotted the “occasional use” bit- In that case definitely go for a good brand with a four year warranty. Car batteries thrive on regular runs and hate being left unused for any length of time.