From this page of the guide to Valheim, you will learn how to find Cloudberries, a fruit that can be eaten immediately or used in other ways.
Cloudberries are a type of food you can find while exploring the vast world of Valheim. Cloudberries can be consumed to gain a bonus of 15 to health points and 20 to stamina points, or used as an ingredient to prepare Mead base: Medium stamina. Nordic Raspberries are also useful for taming Lox.
Cloudberries can be found in various locations in the Plains biome. Cloudberries have a very distinctive appearance and puffy, yellow fruits - you definitely won't miss them.