Hi Matthew, welcome to the forum as well ;-)
As Broch stated, your needs will change as you start investing time in you new land. It would help to state you will be doing, or intend to do, and importantly how long you intend staying there at any one time.
One is assuming there is road access, so any full on work using chainsaw etc, can be done in comfort, without having to carry it all via a single pedestrian track/foot path?
If it is just a few tools, lunch, camera and note pad, etc. You could get away with anything from a 12 to 30 litre bag.
From experience I would keep below 60 litres.
I am a big fan of the 5.11 rush bags, they are comfortable for me, even under heavy loads. Have the rush 12, that I use for work, rush 24 for day hikes and day bushcrafting, for camping I use the rush 72.
They will not break the bank price wise, as there are always deals to be had for online stores, they are strong and comfortable.
Others will have there recommendations, but these are mine from my experience, and I have walked 1000s of miles under full load with these bags.
Another note of recommendation, redback dealer boots are bomb proof, in my job and past jobs I would wear through a pair of boots every year (soles and leather worn away)....i bought my current redback boots in 2018, and have only just last week changed the insole, brilliant boots that get worn every day.