I like to use a cup first then transplant to its final home when it is about 1.5 times the size of the cup.

As for the seed bank I have no input for that I only plant seeds I acquire myself, too paranoid to order online lol.

That soil looks just fine, just be careful using nutrients with soil that already has fertilizer in it u don't want to love ur plants to death and make sure u dilute to around 1/4 of the instructions.

Just keep reading around the forums and make google ur best friend u can always find answers on there if u need help fast