MAIN QUEST or Side quests

[Arthur Morgan]

should i focus first on side quest and then doing main quest, or should i complete the mainquest before i focus on doing side quests ?

[TonyGun]

There isn't a black & white main quest vs. side quest in this game

There is a list of 'Odyssey' quests which Layla and by extension the eagle bearer starts off

There is a list of 'world / people' quests which has mostly to do with the eagle bearer's life and your exploration

Both of these types of quests' storylines split and merge, again & again, many times over the course of the game

There will be 'supporting quests' which are sub-quests of a main tree. Sometimes you need to do them in order for the parent quest to proceed, and sometimes they are optional

The actual 'filler' quests are dynamically generated and from the message boards

The best thing to do is hit up all the NPCs you meet along the way and look at the msg boards along the way so you have multiple quests active. This isn't like RDR where if you choose one quest, the other quest NPCs become hidden until you've finished that one quest. Multiple events can happen all over the game world at the same time & place.

[Jimi]

Just do whatever you feel like. It's an open world so you deceide what you do next.
Mixing it up is probably best so you can level up and get more immersed in this story and the world. Have fun!

[jimbo bamboclaat]

Explore all lands.
Grab all possible quests.
Enjoy it