Hi, I’m planning to install 2 in ground soccer poles for my back garden area, I have 2 questions how would I prop (stabilise the pole while it dries?) as it’s in the middle of no where and have nothing to screw too? Should I be using clamps and some timber? It’s circular so was worried about what to use.
also to ensure that they both align so to speak. I’m on a quite a large block of land- the distance in between them is about 40 odd meters. Should I be using a string line?
pic is a reference on what I ordered

TIA