Am new to the game so I wanted to know if these are good pokemon to get early on and in the future

[Heartrime𓂀]

If they are what Pokemon should I add to the team? If not what Pokemon would be good to use with Treecko or Torchic I ask as I heard the game is hard 

Torchic or Treecko

 

Aevian Feebas 

 

Nidoking to Zygarde

 

Dedenne to Aevian Mareep

 

Sylveon

 

I want to at least use 2 Aevian forms