Today I have checked on my quickbooks and found that it’s added over 200 transactions that were from before I became self employed?

Thanks for posting to the Community, @newtonj1985.

If you don't want these transactions categorized in QuickBooks, I suggest excluding these items all at once.

Please make sure to uncheck the transaction boxes you wanted to categorize.

Let me show you how:

1. Go to the Transactions menu.
2. Check the box beside DATE.
3. Click the Exclude 🚫 button.
4. Hit Apply.
   

Well done! You have now cleared the old items.

For more details about removing items in the Transaction menu, you can refer to this article: Exclude or delete transactions.

Also, I'll add this article as your reference if you wanted to split transactions in more than two Schedule C-categories: Split and Exclude Transactions.

Please feel free to leave a message or tag me (@Jovychris_A) if you need further assistance. I'll keep my notifications open. Stay safe!