Pruning on Day 19 to early ?

Never take off more than 1/3rd of the plant and should be fine. The only thing i'd prune this early is something i know i will not use later. e.g. i remove the 2 lowest axillary buds ("branches") because I know they won't be used in my canopy when it matters. I do this once they are large enough i can snip them without damaging the plant or get a partial cut due to tiny size etc. unless you are growing tiny plants, i wouldn't remove fan leaves to get light penetration for a 1-2 node side branch. A little stretch early on for this lower growth can be a good thing. Can't have 20 colas in 6in x 6in central area, can we? Maybe, in a sea of green context, it would be beneficial but even that i'd be skeptical. Bend it around the leaves where you can. that's usually good enough to prevent excessive stretching of lower branches. leaves power growth in 4 different ways including light absorption. fewer leaves = slower growth. It is rarely a net-positive to remove leaves without very good reasons.