leaves blocking light?

You will have more out of it if you just let it grow and stretch. The branches will grow out eventually, maybe in a slow pace for now. But even slower if you cut half your plant. So just watch your beauty and spoil her, maybe some karaoke or tell her a story.👌

Plant is 6" tall how the hell can it block anything.

No, don't remove leaves if you can avoid it. the stuff lying on the substrate is okay to remove. LST - use an anchor so it doesn't pull through the substrate. Remove anything pointing straight down into the dirt just for airflow and it's not going anwhere on that vector anyway. you tend to get too many branches too tightly together on lst anyway. Probably won't hurt to remove any pointing down. That might eliminate crowding on its own. Should always work backward from an intended canopy. shoot for ~3 colas per sq ft, give or take. More doesn't improve yield, just clogs shit up and spreads out bud mass more. From there, you plan out the most efficientn way to get there whether through training, topping or any combination. Otherwise you end up with at tangled mess of branches competing with each other. So how big is the space? how many branches you got? start spreading them out evenly and once in position, let it go vertical. shouldn't have any crowding issues doing this. Unwanted growth can be identified and pruned off before it wastes resources. Leave the leaves.. just unnecessary growth tips (unwanted axillary buds) Ahh, is this an autoflower? that changes things if so.. i'd just spread things out as best you can and if some growth is too tight, remove it. a bunch of clogged up branches never ends well.

I would not defoliate, particularly plants that size, those branches need the big fan leaves to make the energy that they need to grow. Lollipopping the lower portion of the plants and removing small weak (branch) growths would be my preferred option. Otherwise, wait until any leaves turn yellow from lack of light before cutting them off. Remember........... more leaves = more energy being made = more (and faster) growth. Also, plants are looking quite over fed...........which can cause excessive leaf growth at the expense of general growth and especially flower growth.