I can't tell you anything about V Rising but if you've never been into survival games, Valheim is a good start I guess. Unlike many other games in that genre Valheim doesn't have the constant struggle for not dying due to starving. You can't starve here, you just have low health and stamina regeneration. So the game rewards you for eating by just beeing stronger.
In terms of survive Valheim can be easy, if you do things right, but as well merciless if you do things wrong like going into biomes that you are not prepared for. You start in meadows biome where its chill and enemies aren't strong. Once you step into dark forest (the next biome) the game warns you only one time to think about if you are prepared enough. After that no further warnings so venturing into further biomes is in your responsibility.
If you die, you loose your gear where you died in a tombstone and wake up in your last registered bed. You then need to walk to your tombstone to get back your stuff.
So be careful, plan ahead and prepare for adventures.

About building you can just build the most necessary things or spend hours and hours into building a huge base/village and decorating to get a cosy viking home.

Totally worth the money if you ask me.