Its recommended to start a new world to experience the changes to full extent and if you don't want to spoil yourself.
But it's not strictly necessary.

ive decided to start fresh with the new content and enjoy a new valheim adventure

so i can but i shouldn't explore hardly. or just wait lol thanks guys/gals

Please see: https://steamcommunity.com/app/892970/discussions/0/3032599335589067000/

Thank you!

Originally posted by G1NG3RCL4U5:

i really want to start playing this again and i dont want to wait lol

Already explored areas won't be affected by the update so you will have to travel further to see the new stuff.
The devs recommend a fresh start though for best results.