What changes in the structure of the body allowed the first land plants and the first amphibians to appear?

Thanks to random mutations, adaptation of living organisms to the environment and natural selection, terrestrial plants and amphibians have appeared on our planet. This was possible due to the appearance in plants and animals of some adaptations for life on land. In animals, these were the lungs, since oxygen is needed to maintain life. They also received limbs for free movement on land. Plants are given a root to absorb water, a stem, leaves, buds and flowers.