Totally agree with Mr. J.... don't overthink it or over complicate things ESPECIALLY for your first grow.
Also, agree with bushed and Aridbud, stuff like rockwool is unforgiving and you have to make sure it's only moist, not soaking wet.
I would recommend a cheap bag of soil raising mixture and a warm window of heat mat for germination, and keep it away from intense light until it's got a few leaves.
To me (i could be wrong) the way your seedling is white it looks like light bleaching from too much light, for a sensitive little sprout.
Be a minimalist with seeds/seedlings and don't practice with expensive seeds.