Get your taxes done using TurboTax

Actually you can just enter it as Other self employment income or as Cash or General income. You don't need to get a 1099MISC, 1099NEC or 1099K. Even if you did you can enter all your income as Cash. Only the total goes to schedule C. You should be entering the income from your own records.

Sorry I don't know what to tell you about inventory.  Just try to skip or continue through that part.