When in doubt check what other people did.
https://www.tiktok.com/@cerberus.ramos/video/7178314802274651398
Looks like a long tunic or undertunic with a belt and leather apron over that.
https://www.amazon.com/Medieval-Viking-Pirate-Tunic-Made-Green-XL/dp/B07YYMSZM1
Pants look like the cosplay stereotypical baggy trousers/puffy pirate pants/aladdin pants.
https://www.amazon.com/PERDONTOO-Casual-Elastic-Waist-Hippie/dp/B08K2YQKBS/