I've got just over 195 hours in Valheim so far and almost all of that has been solo. It's totally playable alone, and I really enjoyed it.

There's also a Valheim forum where you can look for other players:

https://steamcommunity.com/app/892970/discussions/3/

You can also try Discord.

https://discord.com/invite/valheim

As of right now there are 53,000 players on the discord. I'm sure you could find at least one or two people to join you.