I'm curious software options
Assume you're on Windows 10 64bit, with at least 8GB of RAM.
First thing to try is before game launch, go into Task Manager and turn off any other apps which are running. Make sure there isn't any full disk scan or indexing going on.
If you're playing online, what's your internet connection like? I'd guess you need decent broadband for that.
Your CPU is fine, so if it's hardware, that's likely to be the problem. Valheim's recommended specs on Steam say GTX 970—that's a desktop GPU, which will be more powerful than a laptop, and then there's the considerable gap between 770 and 970.
Do you maybe have 2 GPUs? I had an Alienware 17 for a few years, and it had 2. Of course, I have no idea if a/the game can use both.