Having doubts about how I run my game as a new dm. Help apprecieated! /u/Gajiba DnD: Roll for Initiative!

OK so as my first DMing experience I made a small world with 3 countries and a little bit of lore attached to it. There is a lot of politics. Segregation is everywhere in this world. (it’s not actually the whole world, countries outside this continent are hinted at but they are not a part of the story yet.) Orks live in their own country along with goblins. Humans, dwarves, elves, halflings have their own country. And there is a third island country off the coast where there are outcasts of all races. The party all work for the King of the human(+others) country and they are on a mission to kill an ork general. So there is a lot of travelling. They are trekking from the very north of the continent to almost the very south. During the travel I make the party encounter all sorts of things. And in my mind all of these things lead to side stories they can follow. They are not random encounters. For example, just outside the capital where they first met, there was a Kobold cave and in the end they found a dragon tooth. I plan to eventually have the owner of that tooth greet them (with fire) that might lead to more. I just have so many plans for side stories that they might explore during their travels. On our most recent session, the party found a cultist lair and I also plan on expanding that. A worlwide network of these cultist and this might lead them into the outer planes(?) Do you think having all these side stories they might follow and encounter during their travels detract from the experience? Should they follow a more linear story with their quest? Would it take too long for them to follow the main quest? I’d love your feedback on it. Thanks! (this is 5.5e if it matters)

OK so as my first DMing experience I made a small world with 3 countries and a little bit of lore attached to it. There is a lot of politics. Segregation is everywhere in this world. (it’s not actually the whole world, countries outside this continent are hinted at but they are not a part of the story yet.) Orks live in their own country along with goblins. Humans, dwarves, elves, halflings have their own country. And there is a third island country off the coast where there are outcasts of all races. The party all work for the King of the human(+others) country and they are on a mission to kill an ork general. So there is a lot of travelling. They are trekking from the very north of the continent to almost the very south. During the travel I make the party encounter all sorts of things. And in my mind all of these things lead to side stories they can follow. They are not random encounters. For example, just outside the capital where they first met, there was a Kobold cave and in the end they found a dragon tooth. I plan to eventually have the owner of that tooth greet them (with fire) that might lead to more. I just have so many plans for side stories that they might explore during their travels. On our most recent session, the party found a cultist lair and I also plan on expanding that. A worlwide network of these cultist and this might lead them into the outer planes(?) Do you think having all these side stories they might follow and encounter during their travels detract from the experience? Should they follow a more linear story with their quest? Would it take too long for them to follow the main quest? I’d love your feedback on it. Thanks! (this is 5.5e if it matters)