Hey there, brother! Healthy looking plant you got there! It looks a bit short (as of day 21, anyway) to start LST. You may want to raise your grow light a bit to try and induce a little stretching. I always find it's easier to do LST when the stalks are a bit longer.
They sell some plant training wire that is wrapped in soft rubber -- I use that to avoid it cutting into my plants. I'm doing DWC too - and I use my bucket handle and the level tube holder to anchor. Unfortunately, the buckets don't lend themselves well to LST. But you can definitely get it done! I usually do it around weeks 3-5. After week 5 or 6 the plants start to get more woody and aren't as flexible. But, you'll see the buds pointing back upwards usually after a couple of hours! There's not much to "learn" -- in my opinion -- but you just want to make your bud sites as flat as possible to even out the light distribution. You'll find that some buds will shoot up a bit higher, still. But you definitely get a better yield and light distribution with LST! Also, I top my plants most of the time (unless I'm low on tent space, which I am now). I hear a lot about not topping autos, but I seem to get way bigger yields when I top. Check out my Northern Lights -- I topped that plant a couple times on the main stalk (nowhere else), and then I did LST.
Good luck with the grow brother!