How do I fill out the inventory expenses?

I am trying to figure out how to fill out the inventory expenses online and it's got me confused. Is the EOY valuation a total amount of the value I paid for the items that I only have left in my inventory? What are my purchases?

I wholesale random items I find. My COGS should be the amount I paid for only the items I sold, correct? If that's the case, I do not understand why it is calculating it as "Cost of purchases minus EOY valuation"

My BOY value is 0 since I had nothing before this year. I bought and sold items in the same year so I would not add those in the EOY valuation, correct?

I bought the items I sold this year at $260.50 (COGS, right?) and I sold them for $408.61. My EOY valuation for the items I still had in stock on 1/1/21 was $172.65.

What am I doing wrong here?

Another question, my business did more than just sales and had a lot of services provided. In the end of the thing to fill out inventory expenses it says that "sales are. . ." and it's the total amount of my whole business income, including services. Is this going to be a problem?