Take a moment to figure out how the Map Generator tool works and it will be your best friend.

Use it to find a Trader in your world, they are relatively obtuse to find if you aren't specifically looking for them, and even still it can sometimes take many hours to find the Trader if your world generation is unlucky. But the Trader is your key here because he's your best shot at getting a fishing pole, and currently your only source of bait for said pole. Be sure to bring materials for a portal when you set out so you can return to the Trader at any point.

https://valheim-map.world/