The issue is that QB is perpetual, anything you enter, now or in the past, affects the balances of the accounts now. So entering historical sales, deposits, expenses etc are not something you can do easily, if at all.
This year the best thing you can do it get the sales data from ebay for the years transactions that are not in QBO and add the QBO transactions when preparing for the end of year taxes.
LLC is not a business type, an LLC just protects your personal assets in the event a court judgment goes against the business. You are either a sole proprietor, a partnership registered with the state and feds, or a C- or S-corporation also registered. Those are the only selections possible when filing taxes.
Whether you keep sales receipts in QB or leave them at ebay is a personal choice, what matters is the income and expenses post in QB.
