Nick here from Shopify.
Great to hear you have started a store and good questions.
It's hard to know exactly if the factory where your products are known the shipping method without some more details or taking a closer look into your store admin/ Oberlo admin. The content team at Shopify wrote a great blog post about ePacket and everything there is to know about it which you can read here which might help shed some light for you. The content team at Oberlo have a great YouTube video also going into detail of exactly how ePacket works which you can see below.
The majority of the products in the Oberlo marketplace are eligible for ePacket delivery, but not all of them. But should you have any other questions about this, I would recommend reaching out to the Oberlo support team directly here.
Regarding your question around fees, this would be determined primarily by what payment gateway you are using. You mentioned you are based in Hungary and would need to use a payment gateway which Shopify is partnered with out of Hungary. You can see these gateways here. Your best bet would be to reach out to the gateways you are interested in and ask them directly about their fees.
I hope this helps!
All the best, Nick