You aren't even close to needing LST. It'll do more harm than good at this stage. You want some sort of a structure before even considering LST. You want a few sets of nodes 1st bro. Then depending on your strain. You wanna bring out the lower nodes as far as you can and tie them down so they have time to turn up into the light and then go up to the next set and set them a lil shorter so you make kinda an Xmas tree or bush, again depends on the strain. Indica is more bushy. And sativa is like an Xmas tree.
There really is no need to stress over something so small bro. lst is great and all. But you'll be surprised at how much you'll get away with it if you just let autos do their thing for the 1st couple of weeks and let them be. I've a good few diaries were I've done LST and some were I've berly touched (yet). But leave them be let them get around 15-20cm tall about 4-5 sets of nodes and then apply LST. Good luck pal