I’m interested in trying out a tarp instead of a tent. Which knots do you use most often when setting up a tarp? What do you consider essential knots?

I’m curious to hear what people have managed to get away with.
I’ve just swapped out my gear and am not quite ultralight, base of about 6.5kg.
I frequently am carrying 17+kg in a knapsack sprayer around my farm, and I don’t find it uncomfortable. It has a rubbish harness, just thinly padded shoulder straps.
Having done a 4 day hike with a max carry of about 14kg in my pack and not really finding it any easier than with the sprayer I’m now wondering if I can drop the waist belt. I do find myself leaning into the straps more without the waist belts. Worth noting that I find the waist belts uncomfortable some of the time due to pressure on my IT band. Anybody tested the boundaries and found it works for them.

Im looking to replace my patagonia better sweater for backpacking as its just way too heavy and bulky and found myself looking at alpha direct. Now i live in NC and backpack mostly western nc or west Virginia where it doesnt get too cold but i personally run VERY cold so by the fall the nights are cold to me. I want to also wear this as a outer layer with just a sun hoodie while hiking in the winter when temps get too low but am worried that 120gsm is too warm for winter hiking(30-40f ish). I would go with the 120 if it was just a at camp layering system but i also need a layer for cold days while hiking. Would yall say 90gsm would be warm enough at camp with a base layer, down jacket(decathlon mt500), and outer shell in 20-35f or do yall recommend the 120 for both situations? Thanks for any advice!