Hello there, @tropicislepoolan.
I'd like to help and get you back in working order. Can you specify the error or issue you're having within recording the information of your purchase? This way, I'll be able to check if there are related issues on my end.
Additional details are appreciated. Nonetheless, you can record the information in the Category or Item details of the purchase order. I've added a screenshot below for reference. 
You can also check this article to learn more about purchase order in QuickBooks Online (QBO): Create purchase orders in QuickBooks Online
I'm also adding this helpful article that can guide you in case you want to learn how to copy an estimate to your purchase order: Copy an estimate to a purchase order
Should you have other concerns in the future, you can always contact us anytime by leaving a comment below.