My First Grow

Unless you are in a very arid region, you shouldn't need a dome for a seedling. 20-30% rh might be wise to put a dome on and cut soem holes in it until it is an appropriate RH% for your temperature - vpd chart is a visual aid for this. You want a slightly slower rate of transpiration (i.e. lower vpd than for mature vege or flower) early on, but too slow and you impede growth. I've read different suggestions but .8-.9 is probably fine. I'm usually above that, and the impact must be tiny. Circulation fan only needs to cause a little jostling of the plant. Definitely don't point it directly at it. A little twitch of a leaf here or there is fine.