Transferring into a slightly different soil and when to use nutes

it's a very good idea to start the seed in happy frog and use ocean forest when they are older. ocean forest can be quite nutrient-rich and can burn young plants. ideally, with autos you want to start them in their final pot to avoid the transplant stress. this is because any stress the plant experiences will stunt the plant a little and lower overall yield. next time growing autos try filling the final pot size with ocean forest and then digging a hole in the middle and add happy frog until its full. then plant the seed in the happy frog. that way the plant will have a little barrier it has to go through to hit the nutrient-dense soil that would burn it. For now, I would just wait until you have a good root structure so the soil stays together more when you transplant it. or if its one of those peat or coco starter pots you can just bury that in the final pot and the plant will grow through it.