About Covenant

This might be a very stupid question but will the covenant attack the Humans because I watched the trailer and I saw covenants chase the UNSC Infinity, I remember in Halo 3 Arbiter fought on the humans side so do they attack the Humans in Halo 4?
also I don’t remember the ending in Halo 3 so I don’t know if anything changes between the covenant and humans in the ending.

The covenant attack humans yes.

Storm Faction

This Covenant is like another colony, they are still highly religous and don’t know that the Human-Covenant war has ended. You should read the Thursday War if you want to know more about them.