I keep using the same exact seed to generate a 'multiVerse' of worlds, each being the same copy, so I know where the resources are located and negates any 'surprises'....some I collect Oak Tree seeds in, some I go fishing in, I use the same seed but for different reasons.

My suggestion is to try it out first without using other worlds. I have multiple playthroughs playing it that way and I thoroughly enjoyed it. ALOT of other people do not like the grind but ALOT of people really do like it the long drawn out way. If you want to rush it, it helps alot, If you want it to take a long time, just use the resources in your same world.

Don't worry about using other world seeds for anything right now. You don't need it. You have ALL the resources you need at this point to get through the game. See how you go. Obviously if you hate the grind or the idea of mobs flattening your home base build, use multiple seeds to traverse the Valheim "universe".

If you want to use another world for building or resources, think of it as just another address in the same world. 1A is your boss game where you do all your fighting, exploring, etc. 1B is your home/resource address. You can fill your pockets in 1B and log into 1A to transport things if needed.

Its easy, you see your characters and worlds are seperate, so you can choose your character and make a new world and the character with all their stuff and skills can enter that new world.

using another world to farm also cuts down on lots of time with regards to getting resources like metals back to base. you can be at a mine or crypt in the other world, load up on ore, log back in to your main world where you logged out standing next to your storage chests and.......BOOM! put your ore in storage and log back in to the other world where there you are still in the crypt :-)

it is cheesy but.....oh well.

for the first boss you should avoid worries about materials from other seeds.
it is the same difficulty and merely wastes your energy with the game and distracts from the game experience for beginners.

building in valheim allows you to preserve the look of an area without stripping it bare for materials. then another seed can preserve your aesthetic standard as a second source. it is more relevant in multiplayer building.

the second boss presents more variables and you will see more choices where resource logistics arise as you go further.

in the game you are presented with the choice of which character to use and then which world to play upon. you require two worlds and then go back and forth between them with pockets full...or empty.

The main goal of world-hopping is to work around some game mechanics that some people dislike:

* it allows you to move ores around very quickly, circumventing the "no ore through portal" rule.

* if you kill bosses in one world and use another world to build/craft/explore you never need to worry about raids. This circumvents the mechanic forcing you to deal with random events or having to defend your base

* I've seen some people claim that it makes it easier to collect a lot of resources. Say you find a great swamp in a world, then you can go directly to the "same" swamp in an identical copy and get iron without the need to hunt for more crypts.

If you haven't even beaten the first boss, everything you collect is renewable so it would be pointless.