Can you teach me how should I answer these questions please..

Question

Why the events are significant?

First mammals:
First primates:
First modern humans:

Answer 1

Also, there are more questions and I've done these.

First fish: fish did brief visits to the land and eventually they evolve into amphibians.

First land plants: plants were the first living things to move into land.

First amphibians: Amphibians only had to be in water to breed. Amphibians later evolved into insects which didn’t need to go into the water.

First reptiles: Reptiles evolved from insects and solved both main problems found in land. They lay eggs with dry shells and had skeletons rather than outer shells.

Answer 2

Some of the first mammals evolved into primates.
Some of the primates evolved into humans.