can I sell stuff on the marketplace
Yes, if it is of high enough quality. Have you submitted to EPIC?
Nearly everybody can sell stuff on the marketplace -> just take a look at this thread: https://forums.unrealengine.com/showthread.php?29760-Marketplace-Info-and-Guidelines-READ-FIRST + https://www.unrealengine.com/marketplace/marketplace-submission-guidelines
I belive that seller needs to be legally registrated. In our country It is a lot of bureaucracy if you want to obtain Taxpayer ID and tax forms, also you will need to pay for it.
I believe Unreal Marketplace will deal with individuals ie. you don’t need a formal registered company. In your country you just need to worry about how to report the income if/when you get paid by Unreal (via PayPal I believe)?
I don’t think there is that weird thing like Apple where you have to get a US tax file number etc?
As far as I know you get the money by bank transfer (so directly onto your bank account)
The only thing that you have to worry about are the taxes that you have to pay in your country -> e.g here in Austria the revenues earned with the marketplace will be calculated into the “income tax”.