Potted plants are generally used.
The best potted plant is mixed soil. (40% soil, 40% rotten leaves or other plants, 20% sand) I like loose, humus soil with good drainage and air permeability.
Usually, you can't water the soil too much, just keep the soil moist. The Aralia elata in your picture is because the soil is too dry and short of water, resulting in drooping leaves. Water should be sprayed on the leaves frequently in summer, and fertilizing the seedlings can be done by people. . . . . Seedlings generally do not need fertilization.
If you move indoors in winter, you will freeze to death and hurt your roots. The soil should be dry in winter, and you shouldn't water it too much.
I hope it helps you.