Long time lurker first time poster! I've been learning a lot from reading current and old post on this forum and also been inspired by a lot of your fantastic trees.
I've started Bonsai in the last 4 months as a tool assist with post military life and the associated baggage one leaves with. I have a few trees im just trying to keep alive and simply care for like a child trying to ensure their development is sound!
I am however at a point with my Japanese Maple where I am in need of some advice. I am a novice and have found some subjective opinions, some contradicting opinions and some just confusing! So i do appreciate all advice given but will ask that those who are going to roll their eyes, groan and offload their double barrel in my direction to remember we all had to start somewhere!

So I've had this Maple for approx 3 months over which time all I've done is water it and prune it high to try and thicken the trunk low. It was sitting in full sun all day, however with the hot dry and windy days I've had in my area i was experiencing, what i believe to be, a lot of leaf burn. So I've since moved it to an area where it gets the morning sun from 6-11am, then move it to a shady area out of the wind. Seems to have done the trick as i no longer have black tips of leaves or dead ones.
What I am now after is advice on thickening the trunk. There is no taper (i haven't seen the nebari or roots yet either so that will be a surprise when i pull it out) and as you'll see simply looks like a stick with branches! I understand the concept of thickening a trunk (ground planting, growing long branches low so energy is focused lower in the trunk, trunk chopping etc etc), however not all can be done at once and some techniques cant be done this time of year...or that is my understanding and hence why i'm here; clarification/guidance!
I would like to see this as an informal upright as the end result. So id like to put the tree on the correct direction during its development into a Bonsai.
So...Should/could I trunk chop now (as seen in the photo it has had a previous trunk chop)? Could/should I put it in a colander now and ground plant? Could I air layer it so as not to waste anything from a trunk chop? Should I just let it go and just keep watering and look at some work during or after winter?
I live in the country 40km South West of Brisbane near Beaudesert so that should give you an idea of weather and climate (if you now where that is!)
Again, please be gentle on me!
Thanks for your help!